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Journal articles on the topic 'Cell surface molecules][Morphogenesis'
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Niessen, Carien M., Deborah Leckband, and Alpha S. Yap. "Tissue Organization by Cadherin Adhesion Molecules: Dynamic Molecular and Cellular Mechanisms of Morphogenetic Regulation." Physiological Reviews 91, no. 2 (April 2011): 691–731. http://dx.doi.org/10.1152/physrev.00004.2010.
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This review addresses the cellular and molecular mechanisms of cadherin-based tissue morphogenesis. Tissue physiology is profoundly influenced by the distinctive organizations of cells in organs and tissues. In metazoa, adhesion receptors of the classical cadherin family play important roles in establishing and maintaining such tissue organization. Indeed, it is apparent that cadherins participate in a range of morphogenetic events that range from support of tissue integrity to dynamic cellular rearrangements. A comprehensive understanding of cadherin-based morphogenesis must then define the molecular and cellular mechanisms that support these distinct cadherin biologies. Here we focus on four key mechanistic elements: the molecular basis for adhesion through cadherin ectodomains, the regulation of cadherin expression at the cell surface, cooperation between cadherins and the actin cytoskeleton, and regulation by cell signaling. We discuss current progress and outline issues for further research in these fields.
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Bazzoni, Gianfranco, Maria Grazia Lampugnani, and Elisabetta Dejana. "The Role of Endothelial Cell-to-Cell Junctions in Vascular Morphogenesis." Thrombosis and Haemostasis 82, no. 08 (1999): 755–61. http://dx.doi.org/10.1055/s-0037-1615908.
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IntroductionAdhesion of endothelial cells (ECs) to one another and to the extracellular matrix is mediated by various surface receptors These surface receptors belong to several families of ubiquitously expressed cell adhesion molecules, such as cadherins integrins, immunoglobulins, and proteoglycans. Besides merely providing attachment sites, most adhesive receptors interac with cytoskeletal and cytoplasmic molecules and, thus, contribute to the regulation of cell morphology and signaling.Adhesion requires refined modulation to sustain the process of new vessel formation or angiogenesis. Adjoining cells mus act in concert to finalize migration and proliferation and organize into a three-dimensional network of patent tubes. Some of the molecules involved in these cell-to-extracellular matrix and cell-to-cell interactions have now been characterized. The intracellular signaling pathways activated by these molecules are, on the contrary, still rather obscure. Moreover, the adhesive systems to matrix and neighboring cells can communicate,1-4 adding complexity and coordination to the process.
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Machnicka, Beata, Renata Grochowalska, Dżamila M. Bogusławska, and Aleksander F. Sikorski. "The role of spectrin in cell adhesion and cell–cell contact." Experimental Biology and Medicine 244, no. 15 (June 21, 2019): 1303–12. http://dx.doi.org/10.1177/1535370219859003.
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Spectrins are proteins that are responsible for many aspects of cell function and adaptation to changing environments. Primarily the spectrin-based membrane skeleton maintains cell membrane integrity and its mechanical properties, together with the cytoskeletal network a support cell shape. The occurrence of a variety of spectrin isoforms in diverse cellular environments indicates that it is a multifunctional protein involved in numerous physiological pathways. Participation of spectrin in cell–cell and cell–extracellular matrix adhesion and formation of dynamic plasma membrane protrusions and associated signaling events is a subject of interest for researchers in the fields of cell biology and molecular medicine. In this mini-review, we focus on data concerning the role of spectrins in cell surface activities such as adhesion, cell–cell contact, and invadosome formation. We discuss data on different adhesion proteins that directly or indirectly interact with spectrin repeats. New findings support the involvement of spectrin in cell adhesion and spreading, formation of lamellipodia, and also the participation in morphogenetic processes, such as eye development, oogenesis, and angiogenesis. Here, we review the role of spectrin in cell adhesion and cell–cell contact.Impact statementThis article reviews properties of spectrins as a group of proteins involved in cell surface activities such as, adhesion and cell–cell contact, and their contribution to morphogenesis. We show a new area of research and discuss the involvement of spectrin in regulation of cell–cell contact leading to immunological synapse formation and in shaping synapse architecture during myoblast fusion. Data indicate involvement of spectrins in adhesion and cell–cell or cell–extracellular matrix interactions and therefore in signaling pathways. There is evidence of spectrin’s contribution to the processes of morphogenesis which are connected to its interactions with adhesion molecules, membrane proteins (and perhaps lipids), and actin. Our aim was to highlight the essential role of spectrin in cell–cell contact and cell adhesion.
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Shim, Katherine, Kimberly J. Blake, Joseph Jack, and Mark A. Krasnow. "TheDrosophila ribbongene encodes a nuclear BTB domain protein that promotes epithelial migration and morphogenesis." Development 128, no. 23 (December 1, 2001): 4923–33. http://dx.doi.org/10.1242/dev.128.23.4923.
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During development of the Drosophila tracheal (respiratory) system, the cell bodies and apical and basal surfaces of the tracheal epithelium normally move in concert as new branches bud and grow out to form tubes. We show that mutations in the Drosophila ribbon (rib) gene disrupt this coupling: the basal surface continues to extend towards its normal targets, but movement and morphogenesis of the tracheal cell bodies and apical surface is severely impaired, resulting in long basal membrane protrusions but little net movement or branch formation. rib mutant tracheal cells are still responsive to the Branchless fibroblast growth factor (FGF) that guides branch outgrowth, and they express apical membrane markers normally. This suggests that the defect lies either in transmission of the FGF signal from the basal surface to the rest of the cell or in the apical cell migration and tubulogenesis machinery. rib encodes a nuclear protein with a BTB/POZ domain and Pipsqueak DNA-binding motif. It is expressed in the developing tracheal system and other morphogenetically active epithelia, many of which are also affected in rib mutants. We propose that Rib is a key regulator of epithelial morphogenesis that promotes migration and morphogenesis of the tracheal cell bodies and apical surface and other morphogenetic movements.
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NIKOLAOU, S., and R. B. GASSER. "Extending from PARs in Caenorhabditis elegans to homologues in Haemonchus contortus and other parasitic nematodes." Parasitology 134, no. 4 (November 16, 2006): 461–82. http://dx.doi.org/10.1017/s0031182006001727.
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Signal transduction molecules play key roles in the regulation of developmental processes, such as morphogenesis, organogenesis and cell differentiation in all organisms. They are organized into ‘pathways’ that represent a coordinated network of cell-surface receptors and intracellular molecules, being involved in sensing environmental stimuli and transducing signals to regulate or modulate cellular processes, such as gene expression and cytoskeletal dynamics. A particularly important group of molecules implicated in the regulation of the cytoskeleton for the establishment and maintenance of cell polarity is the PAR proteins (derived from partition defective in asymmetric cell division). The present article reviews salient aspects of PAR proteins involved in the early embryonic development and morphogenesis of the free-living nematode Caenorhabditis elegans and some other organisms, with an emphasis on the molecule PAR-1. Recent advances in the knowledge and understanding of PAR-1 homologues from the economically important parasitic nematode, Haemonchus contortus, of small ruminants is summarized and discussed in the context of exploring avenues for future research in this area for parasitic nematodes.
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Brown, Nicholas H., James W. Bloor, Olga Dunin-Borkowski, and M. Dolores Martín-Bermudo. "lntegrins and morphogenesis." Development 119, Supplement (December 1, 1993): 177–83. http://dx.doi.org/10.1242/dev.119.supplement.177.
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The Drosophila position specific (PS) integrins consist of two cell surface heterodimers, PSl (αPs1βPS) and PS2 (αPs2βPS), which are expressed on complementary sides of attachments between cell layers and are essential for these attachments. Current evidence suggests that the PS integrins bind to components of the extracellular matrix, similar to the majority of vertebrate integrins, but specific Drosophila ligands have not yet been identified. In the embryo PSI is found on the surface of the epidermis and endoderm, while PS2 is restricted to the mesoderm. The integrins are concentrated at the sites where the somatic muscles attach to the epidermis and at the interface between the visceral mesoderm and the endoderm. In myospheroid mutant embryos, which lack the rssubunit, the adhesion between the mesoderm and the other cell layers fails. The PS integrins are also required for the adhesion of the dorsal to the ventral surface of the wing during metamorphosis. PSl is expressed on the basal surface of the dorsal cells and PS2 is expressed on the ventral cells. Loss of PS integrin function in the wing results in balloon shaped wings because of the failure of the two surfaces of the wing blade to adhere to each other. These and other aspects of the phenotypes of mutations in the genes encoding the PS integrins indicate that integrins play an important role in the adhesion of different cell layers to each other and thus an essential role in the morphogenesis of the organism. The use of extracellular matrix receptors in this role may aid in keeping the different cell layers distinct.
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Hirai, Yohei, Derek Radisky, Rosanne Boudreau, Marina Simian, Mary E. Stevens, Yumiko Oka, Kyoko Takebe, Shinichiro Niwa, and Mina J. Bissell. "Epimorphin Mediates Mammary Luminal Morphogenesis through Control of C/EBPβ." Journal of Cell Biology 153, no. 4 (May 14, 2001): 785–94. http://dx.doi.org/10.1083/jcb.153.4.785.
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We have shown previously that epimorphin (EPM), a protein expressed on the surface of myoepithelial and fibroblast cells of the mammary gland, acts as a multifunctional morphogen of mammary epithelial cells. Here, we present the molecular mechanism by which EPM mediates luminal morphogenesis. Treatment of cells with EPM to induce lumen formation greatly increases the overall expression of transcription factor CCAAT/enhancer binding protein (C/EBP)β and alters the relative expression of its two principal isoforms, LIP and LAP. These alterations were shown to be essential for the morphogenetic activities, since constitutive expression of LIP was sufficient to produce lumen formation, whereas constitutive expression of LAP blocked EPM-mediated luminal morphogenesis. Furthermore, in a transgenic mouse model in which EPM expression was expressed in an apolar fashion on the surface of mammary epithelial cells, we found increased expression of C/EBPβ, increased relative expression of LIP to LAP, and enlarged ductal lumina. Together, our studies demonstrate a role for EPM in luminal morphogenesis through control of C/EBPβ expression.
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Clark, Andrew G., Ortrud Wartlick, Guillaume Salbreux, and Ewa K. Paluch. "Stresses at the Cell Surface during Animal Cell Morphogenesis." Current Biology 24, no. 10 (May 2014): R484—R494. http://dx.doi.org/10.1016/j.cub.2014.03.059.
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Yamamoto, A., S. L. Amacher, S. H. Kim, D. Geissert, C. B. Kimmel, and E. M. De Robertis. "Zebrafish paraxial protocadherin is a downstream target of spadetail involved in morphogenesis of gastrula mesoderm." Development 125, no. 17 (September 1, 1998): 3389–97. http://dx.doi.org/10.1242/dev.125.17.3389.
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Zebrafish paraxial protocadherin (papc) encodes a transmembrane cell adhesion molecule (PAPC) expressed in trunk mesoderm undergoing morphogenesis. Microinjection studies with a dominant-negative secreted construct suggest that papc is required for proper dorsal convergence movements during gastrulation. Genetic studies show that papc is a close downstream target of spadetail, gene encoding a transcription factor required for mesodermal morphogenetic movements. Further, we show that the floating head homeobox gene is required in axial mesoderm to repress the expression of both spadetail and papc, promoting notochord and blocking differentiation of paraxial mesoderm. The PAPC structural cell-surface protein may provide a link between regulatory transcription factors and the actual cell biological behaviors that execute morphogenesis during gastrulation.
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Trautman, M. S., J. Kimelman, and M. Bernfield. "Developmental expression of syndecan, an integral membrane proteoglycan, correlates with cell differentiation." Development 111, no. 1 (January 1, 1991): 213–20. http://dx.doi.org/10.1242/dev.111.1.213.
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Syndecan is an integral membrane proteoglycan that behaves as a matrix receptor by binding cells to interstitial matrix and associating intracellularly with the actin cytoskeleton. Using immunohistology, we have now localized this proteoglycan during the morphogenesis of various derivatives of the surface ectoderm in mouse embryos. Syndecan is expressed on ectodermal epithelia, but is selectively lost from the cells that differentiate into the localized placodes that initiate lens, nasal, otic and vibrissal development. The loss is transient on presumptive ear, nasal and vibrissal epithelia; the derivatives of the differentiating ectodermal cells that have lost syndecan subsequently re-express syndecan. In contrast, syndecan is initially absent from the mesenchyme underlying the surface ectoderm, and is transiently expressed when the surface ectoderm loses syndecan. These results demonstrate that expression of syndecan is developmentally regulated in a distinct spatiotemporal pattern. On epithelia, syndecan is lost at a time and, location that correlates with epithelial cell differentiation and, on mesenchyme, syndecan is acquired when the cells aggregate in proximity to the epithelium. This pattern of change with morphogenetic events is unique and not duplicated by other matrix molecules or adhesion receptors.
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Birk, David E., Emanuel Zycband, and Robert L. Trelstad. "Collagen fibril and matrix assembly during morphogenesis." Proceedings, annual meeting, Electron Microscopy Society of America 46 (1988): 232–33. http://dx.doi.org/10.1017/s042482010010322x.
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The morphogenesis of the extracellular matrix requires the synthesis, assembly and deposition of collagen in a tissue specific manner. Collagen synthesis and molecular assembly occur within a series of well defined cytoplasmic compartments, while the assembly and deposition of collagen fibrils, fibril bundles and collagen macroaggregates occurs within a series of extracellular compartments. In the studies described here we focus our attention on the assembly of collagen molecules into fibrils, bundles and tissue specific macroaggregates.The fibroblast has a complex topography which serves to partition the extracellular space into distinct domains where the hierarchical stages in matrix assembly occur. The first recognizable extracytoplasmic domain is a narrow channel which originates deep within the cytoplasm and is open to the extracellular space. These narrow spaces contain single or sometimes 2-3 collagen fibrils and are intimately associated with secretory vacuoles. These channels fuse with each other and with the cell surface giving rise to the second level of compartmentalization and matrix hierarchy where fibrils coalesce to form bundles.
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Bai, X. M., B. Van der Schueren, J. J. Cassiman, H. Van den Berghe, and G. David. "Differential expression of multiple cell-surface heparan sulfate proteoglycans during embryonic tooth development." Journal of Histochemistry & Cytochemistry 42, no. 8 (August 1994): 1043–54. http://dx.doi.org/10.1177/42.8.8027524.
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Heparan sulfate accumulates on cell surfaces and at cell-matrix interfaces, and functionally modulates several of the effector molecules that support the interactions, growth, and differentiation of developing tissues. Using heparin sulfate-specific monoclonal antibodies MAb, we obtained evidence that extracts from rodent embryos contain multiple forms of cell surface-associated heparan sulfate proteoglycan (PG). Taking tooth development in the mouse embryo as a model to further investigate the relevance of this PG redundancy and using MAb against heparan sulfate, antibodies specific for syndecan (syndecan-1) and fibroglycan (syndecan-2) (two distinct members of a larger family of cell-surface heparan sulfate PGs), and specific cDNA probes for these two cell-surface PGs, we obtained in situ evidence for regulated and differential expression of multiple cell-surface heparan sulfate PGs. The unique, distinctive, and coordinated changes in the expressions of these PGs during morphogenesis and differentiation of dental tissues suggest that the various cell-surface PGs are not truly redundant but play important, specific, and potentially complementary roles during embryonic development.
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Brieher, W. M., and B. M. Gumbiner. "Regulation of C-cadherin function during activin induced morphogenesis of Xenopus animal caps." Journal of Cell Biology 126, no. 2 (July 15, 1994): 519–27. http://dx.doi.org/10.1083/jcb.126.2.519.
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Treatment of Xenopus animal pole tissue with activin results in the induction of mesodermal cell types and a dramatic elongation of the tissue. The morphogenetic movements involved in the elongation appear similar to those in normal gastrulation, which is driven by cell rearrangement and cell intercalations. We have used this system to explore the potential regulation of cell-cell adhesion and cadherin function during morphogenesis. Quantitative blastomere aggregation assays revealed that activin induction reduced the calcium-dependent adhesion between blastomeres. Activin-induced blastomeres formed smaller aggregates, and a greater proportion of the population remained as single cells compared to uninduced blastomeres. The aggregation was mediated by C-cadherin because C-cadherin was present in the blastomeres during the aggregation assay, and monoclonal antibodies against C-cadherin inhibited the calcium-dependent aggregation of blastomeres. E-cadherin was not detectable until after the completion of the assay and, therefore, does not explain the adhesive differences between induced and uninduced blastomeres. L cells stably expressing C-cadherin (LC cells) were used to demonstrate that C-cadherin activity was specifically altered after activin induction. Blastomeres induced with activin bound fewer LC cells than uninduced blastomers. L cells not expressing C-cadherin did not adhere to blastomeres. The changes in C-cadherin-mediated adhesion occurred without detectable changes in the steady-state levels of C-cadherin or the amount of C-cadherin present on the surface of the cell. Immunoprecipitation of C-cadherin and its associated catenins revealed that the ratio of C-cadherin and the catenins was not altered by activin induction. These results demonstrate that activin decreases the adhesive function of existing C-cadherin molecules on the surface of blastomeres and suggest that decreased cadherin mediated cell-cell adhesion is associated with increased morphogenetic movement.
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Bhatnagar, Rajendra S., Mark B. Shattuck, Jing Jing Qian, Craig A. Gough, and Steven B. Nicoll. "Theoretical and Experimental Approaches to Identification of a Fiber Surface Cell Binding Domain in Collagen and its Application in Tissue Engineering." Microscopy and Microanalysis 6, S2 (August 2000): 986–87. http://dx.doi.org/10.1017/s1431927600037429.
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Type I collagen comprises between 75-95% of the stationary extracellular matrix of most tissues, forming a continuum in which most of the static cells are anchored. Collagen serves as the track for haptotactic cell migration. The junction between collagen, its receptor integrins, and the cells’ cytoskeleton plays a crucial role in cell differentiation and morphogenesis by serving as the agent for transducing mechanical forces into chemical and biochemical work. The physiological, functional organization of collagen is the solid state in the form of a network of fibers. The only molecules available for engaging the receptors are those located on the fiber surface. Cryogenic scanning force microscopy (SFM) of single molecules of collagen allowed us to correlate surface features with known sequence and stereochemical markers within collagen. Theoretical conformational studies to locate markers for intermolecular recognition and allosteric binding showed that collagen a 1(1) chain residues 766GTPGPQGIAGQRGVV780 generate a distinctive conformation, characterized by a relatively stable (3-bend at the core (Fig. 1) within the triple helical polyproline II conformation extant in the rest of the molecule (1).
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Harrington, Robert J., Michael J. Gutch, Michael O. Hengartner, Nicholas K. Tonks, and Andrew D. Chisholm. "TheC. elegansLAR-like receptor tyrosine phosphatase PTP-3 and the VAB-1 Eph receptor tyrosine kinase have partly redundant functions in morphogenesis." Development 129, no. 9 (May 1, 2002): 2141–53. http://dx.doi.org/10.1242/dev.129.9.2141.
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Receptor-like protein-tyrosine phosphatases (RPTPs) form a diverse family of cell surface molecules whose functions remain poorly understood. The LAR subfamily of RPTPs has been implicated in axon guidance and neural development. Here we report the molecular and genetic analysis of the C. elegans LAR subfamily member PTP-3. PTP-3 isoforms are expressed in many tissues in early embryogenesis, and later become localized to neuronal processes and to epithelial adherens junctions. Loss of function in ptp-3 causes low-penetrance defects in gastrulation and epidermal development similar to those of VAB-1 Eph receptor tyrosine kinase mutants. Loss of function in ptp-3 synergistically enhances phenotypes of mutations in the C. elegans Eph receptor VAB-1 and a subset of its ephrin ligands, but does not show specific interactions with several other RTKs or morphogenetic mutants. The genetic interaction of vab-1 and ptp-3 suggests that LAR-like RPTPs and Eph receptors have related and partly redundant functions in C. elegans morphogenesis.
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Zheng, L., J. Zhang, and R. W. Carthew. "frizzled regulates mirror-symmetric pattern formation in the Drosophila eye." Development 121, no. 9 (September 1, 1995): 3045–55. http://dx.doi.org/10.1242/dev.121.9.3045.
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Coordinated morphogenesis of ommatidia during Drosophila eye development establishes a mirror-image symmetric pattern across the entire eye bisected by an anteroposterior equator. We have investigated the mechanisms by which this pattern formation occurs and our results suggest that morphogenesis is coordinated by a graded signal transmitted bidirectionally from the presumptive equator to the dorsal and ventral poles. This signal is mediated by frizzled, which encodes a cell surface transmembrane protein. Mosaic analysis indicates that frizzled acts non-autonomously in an equatorial to polar direction. It also indicates that relative levels of frizzled in photoreceptor cells R3 and R4 of each ommatidium affect their positional fate choices such that the cell with greater frizzled activity becomes an R3 cell and the cell with less frizzled activity becomes an R4 cell. Moreover, this bias affects the choice an ommatidium makes as to which direction to rotate. Equator-outwards progression of elav expression and expression of the nemo gene in the morphogenetic furrow are regulated by frizzled, which itself is dynamically expressed about the morphogenetic furrow. We propose that frizzled mediates a bidirectional signal emanating from the equator.
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Slaughter, Brian, and Rong Li. "Toward a molecular interpretation of the surface stress theory for yeast morphogenesis." Current Opinion in Cell Biology 18, no. 1 (February 2006): 47–53. http://dx.doi.org/10.1016/j.ceb.2005.11.003.
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Lombardía, Esteban, Adrián J. Rovetto, Ana L. Arabolaza, and Roberto R. Grau. "A LuxS-Dependent Cell-to-Cell Language Regulates Social Behavior and Development in Bacillus subtilis." Journal of Bacteriology 188, no. 12 (June 15, 2006): 4442–52. http://dx.doi.org/10.1128/jb.00165-06.
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ABSTRACT Cell-to-cell communication in bacteria is mediated by quorum-sensing systems (QSS) that produce chemical signal molecules called autoinducers (AI). In particular, LuxS/AI-2-dependent QSS has been proposed to act as a universal lexicon that mediates intra- and interspecific bacterial behavior. Here we report that the model organism Bacillus subtilis operates a luxS-dependent QSS that regulates its morphogenesis and social behavior. We demonstrated that B. subtilis luxS is a growth-phase-regulated gene that produces active AI-2 able to mediate the interspecific activation of light production in Vibrio harveyi. We demonstrated that in B. subtilis, luxS expression was under the control of a novel AI-2-dependent negative regulatory feedback loop that indicated an important role for AI-2 as a signaling molecule. Even though luxS did not affect spore development, AI-2 production was negatively regulated by the master regulatory proteins of pluricellular behavior, SinR and Spo0A. Interestingly, wild B. subtilis cells, from the undomesticated and probiotic B. subtilis natto strain, required the LuxS-dependent QSS to form robust and differentiated biofilms and also to swarm on solid surfaces. Furthermore, LuxS activity was required for the formation of sophisticated aerial colonies that behaved as giant fruiting bodies where AI-2 production and spore morphogenesis were spatially regulated at different sites of the developing colony. We proposed that LuxS/AI-2 constitutes a novel form of quorum-sensing regulation where AI-2 behaves as a morphogen-like molecule that coordinates the social and pluricellular behavior of B. subtilis.
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Warburton, David, Carol Wuenschell, Guillermo Flores-Delgado, and Kathryn Anderson. "Commitment and differentiation of lung cell lineages." Biochemistry and Cell Biology 76, no. 6 (December 1, 1998): 971–95. http://dx.doi.org/10.1139/o98-104.
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To form a large diffusible interface capable of conducting respiratory gases to and from the circulation, the lung must undergo extensive cell proliferation, branching morphogenesis, and alveolar saccule formation, to generate sufficient surface area. In addition, the cells must differentiate into at least 40 distinct lung cell lineages. Specific transcriptional factors, peptide growth factor receptor-mediated signaling pathways, extracelluar matrix components, and integrin-signaling pathways interact to direct lung morphogenesis and lung cell lineage differentiation. Branching mutants of the respiratory tracheae in Drosophila have identified several functionally conserved genes in the fibroblast growth factor signaling pathway that also regulate pulmonary organogenesis in mice and probably also in man. Key transcriptional factors including Nkx2.1, hepatocyte nuclear factor family forkhead homologues, GATA family zinc finger factors, pou and homeodomain proteins, as well as basic helix-loop-helix factors, serve as master genes to integrate the developmental genetic instruction of lung morphogenesis and cell lineage determination. Key words: lung branching morphogenesis, lung cell proliferation, lung cell differentiation, alveolization, master genes, peptide growth factor signaling, extracellular matrix signaling, mesenchyme induction, alveolar epithelial cells, pulmonary neuroendocrine cells, stem cells, retinoic acid.
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Zhong, Yun, William M. Brieher, and Barry M. Gumbiner. "Analysis of C-cadherin Regulation during Tissue Morphogenesis with an Activating Antibody." Journal of Cell Biology 144, no. 2 (January 25, 1999): 351–59. http://dx.doi.org/10.1083/jcb.144.2.351.
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The regulation of cadherin-mediated adhesion at the cell surface underlies several morphogenetic processes. To investigate the role of cadherin regulation in morphogenesis and to begin to analyze the molecular mechanisms of cadherin regulation, we have screened for monoclonal antibodies (mAbs) that allow us to manipulate the adhesive state of the cadherin molecule. Xenopus C-cadherin is regulated during convergent extension movements of gastrulation. Treatment of animal pole tissue explants (animal caps) with the mesoderm-inducing factor activin induces tissue elongation and decreases the strength of C-cadherin–mediated adhesion between blastomeres (Brieher, W.M., and B.M. Gumbiner. 1994. J. Cell Biol. 126:519–527). We have generated a mAb to C-cadherin, AA5, that restores strong adhesion to activin-treated blastomeres. This C-cadherin activating antibody strongly inhibits the elongation of animal caps in response to activin without affecting mesodermal gene expression. Thus, the activin-induced decrease in C-cadherin adhesive activity appears to be required for animal cap elongation. Regulation of C-cadherin and its activation by mAb AA5 involve changes in the state of C-cadherin that encompass more than changes in its homophilic binding site. Although mAb AA5 elicited a small enhancement in the functional activity of the soluble C-cadherin ectodomain (CEC1-5), it was not able to restore cell adhesion activity to mutant C-cadherin lacking its cytoplasmic tail. Furthermore, activin treatment regulates the adhesion of Xenopus blastomeres to surfaces coated with two other anti–C-cadherin mAbs, even though these antibodies probably do not mediate adhesion through a normal homophilic binding mechanism. Moreover, mAb AA5 restores strong adhesion to these antibodies. mAb AA5 only activates adhesion of blastomeres to immobilized CEC1-5 when it binds to C-cadherin on the cell surface. It does not work when added to CEC1-5 on the substrate. Together these findings suggest that the regulation of C-cadherin by activin and its activation by mAb AA5 involve changes in its cellular organization or interactions with other cell components that are not intrinsic to the isolated protein.
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Chen, Cheng, Hui Chen, Jianping Sun, Pablo Bringas, Yuhua Chen, David Warburton, and Wei Shi. "Smad1 expression and function during mouse embryonic lung branching morphogenesis." American Journal of Physiology-Lung Cellular and Molecular Physiology 288, no. 6 (June 2005): L1033—L1039. http://dx.doi.org/10.1152/ajplung.00277.2004.
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Bone morphogenetic protein (BMP) 4 plays very important roles in regulating developmental processes of many organs, including lung. Smad1 is one of the BMP receptor downstream signaling proteins that transduce BMP4 ligand signaling from cell surface to nucleus. The dynamic expression patterns of Smad1 in embryonic mouse lungs were examined using immunohistochemistry. Smad1 protein was predominantly detected in peripheral airway epithelial cells of early embryonic lung tissue [embryonic day 12.5 (E12.5)], whereas Smad1 protein expression in mesenchymal cells increased during mid-late gestation. Many Smad1-positive mesenchymal cells were localized adjacent to large airway epithelial cells and endothelial cells of blood vessels, which colocalized with a molecular marker of smooth muscle cells (α-smooth muscle actin). The biological function of Smad1 in early lung branching morphogenesis was then studied in our established E11.5 lung explant culture model. Reduction of endogenous Smad1 expression was achieved by adding a Smad1-specific antisense DNA oligonucleotide, causing ∼20% reduction of lung epithelial branching. Furthermore, airway epithelial cell proliferation and differentiation were also inhibited when endogenous Smad1 expression was knocked down. Therefore, these data indicate that Smad1, acting as an intracellular BMP signaling pathway component, positively regulates early mouse embryonic lung branching morphogenesis.
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Zelhof, Andrew C., and Robert W. Hardy. "WASp is required for the correct temporal morphogenesis of rhabdomere microvilli." Journal of Cell Biology 164, no. 3 (January 26, 2004): 417–26. http://dx.doi.org/10.1083/jcb.200307048.
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Microvilli are actin-based fingerlike membrane projections that form the basis of the brush border of enterocytes and the Drosophila melanogaster photoreceptor rhabdomere. Although many microvillar cytoskeletal components have been identified, the molecular basis of microvillus formation is largely undefined. Here, we report that the Wiskott-Aldrich syndrome protein (WASp) is necessary for rhabdomere microvillus morphogenesis. We show that WASp accumulates on the photoreceptor apical surface before microvillus formation, and at the time of microvillus initiation WASp colocalizes with amphiphysin and moesin. The loss of WASp delays the enrichment of F-actin on the apical photoreceptor surface, delays the appearance of the primordial microvillar projections, and subsequently leads to malformed rhabdomeres.
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Hathaway, H. J., and B. D. Shur. "Mammary gland morphogenesis is inhibited in transgenic mice that overexpress cell surface beta1,4-galactosyltransferase." Development 122, no. 9 (September 1, 1996): 2859–72. http://dx.doi.org/10.1242/dev.122.9.2859.
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Mammary gland morphogenesis is facilitated by a precise sequence of cell-cell and cell-matrix interactions, which are mediated in part through a variety of cell surface receptors and their ligands (Boudreau, N., Myers, C. and Bissell, M. J. (1995). Trends in Cell Biology 5, 1–4). Cell surface beta1,4-galactosyltransferase (GalTase) is one receptor that participates in a variety of cell-cell and cell-matrix interactions during fertilization and development, including mammary epithelial cell-matrix interactions (Barcellos-Hoff, M. H. (1992). Exp. Cell Res. 201, 225–234). To analyze GalTase function during mammary gland morphogenesis in vivo, we created transgenic animals that overexpress the long isoform of GalTase under the control of a heterologous promoter. As expected, mammary epithelial cells from transgenic animals had 2.3 times more GalTase activity on their cell surface than did wild-type cells. Homozygous transgenic females from multiple independent lines failed to lactate, whereas transgenic mice overexpressing the Golgi-localized short isoform of GalTase lactated normally. Glands from transgenic females overexpressing surface GalTase were characterized by abnormal and reduced ductal development with a concomitant reduction in alveolar expansion during pregnancy. The phenotype was not due to a defect in proliferation, since the mitotic index for transgenic and wild-type glands was similar. Morphological changes were accompanied by a dramatic reduction in the expression of milk-specific proteins. Immunohistochemical markers for epithelia and myoepithelia demonstrated that both cell types were present. To better understand how overexpression of surface GalTase impairs ductal morphogenesis, primary mammary epithelial cultures were established on basement membranes. Cultures derived from transgenic mammary glands were unable to form anastomosing networks of epithelial cells and failed to express milk-specific proteins, unlike wild-type mammary cultures that formed epithelial tubules and expressed milk proteins. Our results suggest that cell surface GalTase is an important mediator of mammary cell interaction with the extracellular matrix. Furthermore, perturbing surface GalTase levels inhibits the expression of mammary-specific gene products, implicating GalTase as a component of a receptor-mediated signal transduction pathway required for normal mammary gland differentiation.
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Merkel, Glenn J., Charles L. Phelps, and Roger W. Roeske. "Cell surface specific immunoglobulin inhibits α factor mediated morphogenesis in Saccharomyces cerevisiae." Canadian Journal of Microbiology 33, no. 4 (April 1, 1987): 331–35. http://dx.doi.org/10.1139/m87-056.
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Immunoglobulins raised from Saccharomyces cerevisiae a and α mating type cell envelope preparations inhibited α factor mediated morphogenesis of the a cell without inhibiting normal cell division. The Ig responsible for this inhibition was absorbed to both a and α whole cells and heat-killed cells, indicating that the immunoglobulin binding sites were exposed on the cell surface and not mating type specific. Additionally, α factor mediated cell cycle arrest was not affected by the immunoglobulin preparations, implying that the immunoglobulin was not preventing α factor from binding to its receptor.
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David, G., X. M. Bai, B. Van der Schueren, P. Marynen, J. J. Cassiman, and H. Van den Berghe. "Spatial and temporal changes in the expression of fibroglycan (syndecan-2) during mouse embryonic development." Development 119, no. 3 (November 1, 1993): 841–54. http://dx.doi.org/10.1242/dev.119.3.841.
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Fibroglycan (syndecan-2) is a member of a family of cell surface heparan sulfate proteoglycans that interact with adhesion molecules, growth factors and a variety of other effector systems that support the shaping, maintenance and repair of an organism. To investigate this apparent redundancy of proteoglycans at the cell surface, we have studied the expression of fibroglycan in the mouse embryo and compared this expression with that of syndecan-1. The characterisation of mouse embryo cDNA clones that crosshybridized to human fibroglycan-cDNA predicted that murine and human fibroglycan were highly similar in structure. Consistently, the analysis of transfectant cells, murine cell lines and embryo extracts indicated that the murine proteoglycan reacted specifically with monoclonal antibody 10H4 developed against the human protein. Fibroglycan, as detected by monoclonal antibody 10H4 in sections of embryonic tissues, occurred exclusively on mesenchymal cells that represented the putative precursors of the hard and connective tissue cells. No fibroglycan was detected in epithelia or in muscle cells. Areas where fibroglycan was particularly abundant were sites of high morphogenetic activity where intense cell-cell and cell-matrix interactions are known to occur (e.g. the epithelial-mesenchymal interfaces, the prechondrogenic and preosteogenic mesenchymal condensations). The expression of fibroglycan was weak in the early embryo, culminated during the morphogenetic phase and at the moment of cell lineage differentiation, and persisted in the perichondrium, periosteum and connective tissue cells. Syndecan-1, in contrast, was primarily detected in epithelia, and transiently in some mesenchymal cells, with mesenchymal localisations that did not or only partially overlap with those of fibroglycan. In situ hybridization analyses confirmed these expression patterns at the transcriptional level, identifying mesenchymal cells as the major source of fibroglycan production. These data indicate that the expression of fibroglycan occurs along unique and developmentally regulated patterns, and suggest that fibroglycan and syndecan-1 may have distinctive functions during tissue morphogenesis and differentiation.
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Pesch, Yanina-Yasmin, Ricarda Hesse, Tariq Ali, and Matthias Behr. "A cell surface protein controls endocrine ring gland morphogenesis and steroid production." Developmental Biology 445, no. 1 (January 2019): 16–28. http://dx.doi.org/10.1016/j.ydbio.2018.10.007.
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Klaile, Esther, Olga Vorontsova, Kristmundur Sigmundsson, Mario M. Müller, Bernhard B. Singer, Lars-Göran Öfverstedt, Stina Svensson, Ulf Skoglund, and Björn Öbrink. "The CEACAM1 N-terminal Ig domain mediates cis- and trans-binding and is essential for allosteric rearrangements of CEACAM1 microclusters." Journal of Cell Biology 187, no. 4 (November 16, 2009): 553–67. http://dx.doi.org/10.1083/jcb.200904149.
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Cell adhesion molecules (CAMs) sense the extracellular microenvironment and transmit signals to the intracellular compartment. In this investigation, we addressed the mechanism of signal generation by ectodomains of single-pass transmembrane homophilic CAMs. We analyzed the structure and homophilic interactions of carcinoembryonic antigen (CEA)–related CAM 1 (CEACAM1), which regulates cell proliferation, apoptosis, motility, morphogenesis, and microbial responses. Soluble and membrane-attached CEACAM1 ectodomains were investigated by surface plasmon resonance–based biosensor analysis, molecular electron tomography, and chemical cross-linking. The CEACAM1 ectodomain, which is composed of four glycosylated immunoglobulin-like (Ig) domains, is highly flexible and participates in both antiparallel (trans) and parallel (cis) homophilic binding. Membrane-attached CEACAM1 ectodomains form microclusters in which all four Ig domains participate. Trans-binding between the N-terminal Ig domains increases formation of CEACAM1 cis-dimers and changes CEACAM1 interactions within the microclusters. These data suggest that CEACAM1 transmembrane signaling is initiated by adhesion-regulated changes of cis-interactions that are transmitted to the inner phase of the plasma membrane.
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Hafenstein, Susan, and Bentley A. Fane. "φX174 Genome-Capsid Interactions Influence the Biophysical Properties of the Virion: Evidence for a Scaffolding-Like Function for the Genome during the Final Stages of Morphogenesis." Journal of Virology 76, no. 11 (June 1, 2002): 5350–56. http://dx.doi.org/10.1128/jvi.76.11.5350-5356.2002.
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ABSTRACT During the final stages of φX174 morphogenesis, there is an 8.5-Å radial collapse of coat proteins around the packaged genome, which is tethered to the capsid's inner surface by the DNA-binding protein. Two approaches were taken to determine whether protein-DNA interactions affect the properties of the mature virion and thus the final stages of morphogenesis. In the first approach, genome-capsid associations were altered with mutant DNA-binding proteins. The resulting particles differed from the wild-type virion in density, native gel migration, and host cell recognition. Differences in native gel migration were especially pronounced. However, no differences in protein stoichiometries were detected. An extragenic second-site suppressor of the mutant DNA-binding protein restores all assayed properties to near wild-type values. In the second approach, φX174 was packaged with foreign, single-stranded, covalently closed, circular DNA molecules identical in length to the φX174 genome. The resulting particles exhibited native gel migration rates that significantly differed from the wild type. The results of these experiments suggest that the structure of the genome and/or its association with the capsid's inner surface may perform a scaffolding-like function during the procapsid-to- virion transition.
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Letourneau, P. C., and T. A. Shattuck. "Distribution and possible interactions of actin-associated proteins and cell adhesion molecules of nerve growth cones." Development 105, no. 3 (March 1, 1989): 505–19. http://dx.doi.org/10.1242/dev.105.3.505.
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Actin filaments and their interactions with cell surface molecules have key roles in tissue cell behaviour. Axonal pathfinding during embryogenesis, an especially complex cell behaviour, is based on the migration of nerve growth cones. We have used fluorescence immunocytochemistry to examine the distribution in growth cones, their filopodia and lamellipodia of several actin-associated proteins and nerve cell adhesion molecules. The leading margins of chick dorsal root ganglion nerve growth cones and their protrusions stain strongly for f-actin, filamin, alpha-actinin, myosin, tropomyosin, talin and vinculin. MAP2 is absent from DRG growth cones, and staining for spectrin fodrin extends into growth cones, but not along filopodia. Thus, organization of the leading margins of growth cones may strongly resemble the leading lamella of migrating fibroblasts. The adhesion-mediating molecules integrin, L1, N-CAM and A-CAM are all found on DRG neurites and growth cones. However, filopodia stain relatively more strongly for integrin and L1 than for A-CAM or N-CAM. In fact, the 180 X 10(3) Mr form of N-CAM may be absent from most of the length of filopodia. DRG neurones cultured in cytochalasin B display differences in immunofluorescence staining which further emphasize that these adhesion molecules interact differentially with the actin filament system of migrating growth cones. Several models for neuronal morphogenesis emphasize the importance of regulation of the expression of adhesion molecules. Our results support hypotheses that cellular distribution and transmembrane interactions are key elements in the functions of these adhesion molecules during axonal pathfinding.
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Orabi, Ahmed, Maria Bieringer, Arie Geerlof, and Volker Bruss. "An Aptamer against the Matrix Binding Domain on the Hepatitis B Virus Capsid Impairs Virion Formation." Journal of Virology 89, no. 18 (July 1, 2015): 9281–87. http://dx.doi.org/10.1128/jvi.00466-15.
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ABSTRACTThe hepatitis B virus (HBV) particle is an icosahedral nucleocapsid surrounded by a lipid envelope containing viral surface proteins. A small domain (matrix domain [MD]) in the large surface protein L and a narrow region (matrix binding domain [MBD]) including isoleucine 126 on the capsid surface have been mapped, in which point mutations such as core I126A specifically blocked nucleocapsid envelopment. It is possible that the two domains interact with each other during virion morphogenesis. By the systematic evolution of ligands by exponential enrichment (SELEX) method, we evolved DNA aptamers from an oligonucleotide library binding to purified recombinant capsids but not binding to the corresponding I126A mutant capsids. Aptamers bound to capsids were separated from unbound molecules by filtration. After 13 rounds of selections and amplifications, 16 different aptamers were found among 73 clones. The four most frequent aptamers represented more than 50% of the clones. The main aptamer, AO-01 (13 clones, 18%), showed the lowest dissociation constant (Kd) of 180 ± 82 nM for capsid binding among the four molecules. ItsKdfor I126A capsids was 1,306 ± 503 nM. Cotransfection of Huh7 cells with AO-01 and an HBV genomic construct resulted in 47% inhibition of virion production at 3 days posttransfection, but there was no inhibition by cotransfection of an aptamer with a random sequence. The half-life of AO-01 in cells was 2 h, which might explain the incomplete inhibition. The results support the importance of the MBD for nucleocapsid envelopment. Inhibiting the MD-MBD interaction with a low-molecular-weight substance might represent a new approach for an antiviral therapy.IMPORTANCEApproximately 240 million people are persistently infected with HBV. To date, antiviral therapies depend on a single target, the viral reverse transcriptase. Future additional targets could be viral protein-protein interactions. We selected a 55-base-long single-stranded DNA molecule (aptamer) which binds with relatively high affinity to a region on the HBV capsid interacting with viral envelope proteins during budding. This aptamer inhibits virion formation in cell culture. The results substantiate the current model for HBV morphogenesis and show that the capsid envelope interaction is a potential antiviral target.
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Duband, J. L., T. Volberg, I. Sabanay, J. P. Thiery, and B. Geiger. "Spatial and temporal distribution of the adherens-junction-associated adhesion molecule A-CAM during avian embryogenesis." Development 103, no. 2 (June 1, 1988): 325–44. http://dx.doi.org/10.1242/dev.103.2.325.
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A-CAM (adherens-junction-specific cell adhesion molecule) is a calcium-dependent adhesion molecule which is associated with intercellular adherens junctions in various tissues (Volk & Geiger, 1986, J. Cell Biol. 103, 1441–1450 and 1451–1464). In the present report, we have investigated the distribution of A-CAM during avian morphogenesis by immunofluorescence microscopy and immunoblotting. A-CAM appeared at the onset of gastrulation on developing mesodermal and endodermal cells and was then expressed on tissues derived from the three primary germ layers. During embryonic life, A-CAM was constitutively expressed in a number of tissues including the central and peripheral nervous system, myocardium, muscles, notochord, skin and lens whereas it was found transiently in many tissues ranging from the nephritic tubules and the endoderm of visceral arches to ectodermal placodes. In the adult, in addition to the nervous system, A-CAM was restricted to the skin, lens, heart and testis, and exhibited an apparent molecular weight higher than the one found in the embryo. The prevalence and cell-surface modulation of A-CAM could frequently be correlated with morphogenetic events such as mesenchyme condensation into epithelia or cell clusters (e.g. formation of the somitic epithelium, kidney tubules and peripheral ganglia), dissociation of epithelia (e.g. dissociation of the somitic epithelium and segregation of neural crest from the neural tube), separation of cell populations (e.g. fibroblasts and myotubes in the heart) and reorganizations of epithelia (e.g. neurulation). In addition, using electron microscopy, the expression of A-CAM on the surface of aggregating and separating cells could be correlated with the formation and disappearance of adherens junctions. This precisely scheduled control of A-CAM correlated with early morphogenetic events during embryogenesis suggests that this CAM could play a crucial role in these processes.
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Chen, W. T., J. M. Chen, and S. C. Mueller. "Coupled expression and colocalization of 140K cell adhesion molecules, fibronectin, and laminin during morphogenesis and cytodifferentiation of chick lung cells." Journal of Cell Biology 103, no. 3 (September 1, 1986): 1073–90. http://dx.doi.org/10.1083/jcb.103.3.1073.
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We have analyzed the expression and distribution of fibronectin, laminin, and the 140K cell adhesion molecules (140K complex) in embryonic chick lung cells by a combination of biochemical and immunofluorescent approaches. The 140K complex was identified by monoclonal antibody JG22E as a complex of glycoproteins averaging 140,000 Mr and has been implicated in vitro as a receptor for fibronectin and laminin. Our studies provide the first description that the 140K complex is developmentally regulated, and that the 140K complex appears to be involved in adhesion of epithelial and endothelial cells during morphogenesis. We have shown that the 140K complex is expressed in high quantity in embryonic lung cell types, but is markedly reduced in all of the differentiated cell types except smooth muscle. Embryonic lung cells are enriched in 140K complex on portions of cells in close proximity to areas rich in fibronectin. For example, during the formation of airways and alveolar tissues, 140K complex is concentrated at the basal surfaces of epithelial cells adjacent to fibronectin. Likewise, during the angiogenic invasion of capillaries into lung mesenchyme, the 140K complex becomes localized at sites on the basal surfaces of endothelial cells in close contact with fibronectin. Finally, cytodifferentiating lung smooth muscle cells show unusually high levels of 140K complex, fibronectin, and laminin that persist into the adult. In contrast to fibronectin, laminin is found to be uniformly distributed in the basement membranes of differentiating epithelial cells. It becomes prominent in adult alveolar epithelium and airway epithelium concomitant with a reduction or loss of 140K complex and fibronectin at cell-basement membrane attachment sites. Surprisingly, laminin is also present in a punctate pattern in the mesenchyme of early lung buds, however, laminin, fibronectin, and 140K complex are greatly reduced or lost during mesenchymal maturation. Our results are consistent with the active participation of the 140K complex in cell-to-matrix adhesion during morphogenesis of alveolar walls and cytodifferentiation of mesenchymal and smooth muscle cells.
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Hirokawa, Nobutaka. "Molecular architecture and functions of the neuronal cytoskeleton." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 3 (August 12, 1990): 2–3. http://dx.doi.org/10.1017/s0424820100157541.
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In this symposium I will present our studies about the molecular architecture and function of the cytomatrix of the nerve cells. The nerve cell is a highly polarized cell composed of highly branched dendrites, cell body, and a single long axon along the direction of the impulse propagation. Each part of the neuron takes characteristic shapes for which the cytoskeleton provides the framework. The neuronal cytoskeletons play important roles on neuronal morphogenesis, organelle transport and the synaptic transmission. In the axon neurofilaments (NF) form dense arrays, while microtubules (MT) are arranged as small clusters among the NFs. On the other hand, MTs are distributed uniformly, whereas NFs tend to run solitarily or form small fascicles in the dendrites Quick freeze deep etch electron microscopy revealed various kinds of strands among MTs, NFs and membranous organelles (MO). These structures form major elements of the cytomatrix in the neuron. To investigate molecular nature and function of these filaments first we studied molecular structures of microtubule associated proteins (MAP1A, MAP1B, MAP2, MAP2C and tau), and microtubules reconstituted from MAPs and tubulin in vitro. These MAPs were all fibrous molecules with different length and formed arm like projections from the microtubule surface.
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Steffgen, Kristin, Kimberly Dufraux, and Helen Hathaway. "Enhanced Branching Morphogenesis in Mammary Glands of Mice Lacking Cell Surface β1,4-Galactosyltransferase." Developmental Biology 244, no. 1 (April 2002): 114–33. http://dx.doi.org/10.1006/dbio.2002.0599.
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Weis, William I., W. James Nelson, and Daniel J. Dickinson. "Evolution and Cell Physiology. 3. Using Dictyostelium discoideum to investigate mechanisms of epithelial polarity." American Journal of Physiology-Cell Physiology 305, no. 11 (December 1, 2013): C1091—C1095. http://dx.doi.org/10.1152/ajpcell.00233.2013.
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In Metazoa, a polarized epithelium forms a single-cell-layered barrier that separates the outside from the inside of the organism. In tubular epithelia, the apical side of the cell is constricted relative to the basal side, forming a wedge-shaped cell that can pack into a tube. Apical constriction is mediated by actomyosin activity. In higher animals, apical actomyosin is connected between cells by specialized cell-cell junctions that contain a classical cadherin, the Wnt signaling protein β-catenin, and the actin-binding protein α-catenin. The molecular mechanisms that lead to selective accumulation of myosin at the apical surface of cells are poorly understood. We found that the nonmetazoan Dictyostelium discoideum forms a polarized epithelium that surrounds the stalk tube at the tip of the multicellular fruiting body. Although D. discoideum lacks a cadherin homolog, it expresses homologs of β- and α-catenin. Both catenins are essential for formation of the tip epithelium, polarized protein secretion, and proper multicellular morphogenesis. Myosin localizes apically in tip epithelial cells, and it appears that constriction of this epithelial tube is required for proper morphogenesis. Localization of myosin II is controlled by the protein IQGAP1 and its binding partners cortexillins I and II, which function downstream of α- and β-catenin to exclude myosin from the basolateral cortex and promote apical accumulation of myosin. These studies show that the function of catenins in cell polarity predates the evolution of Wnt signaling and classical cadherins, and that apical localization of myosin is a morphogenetic mechanism conserved from nonmetazoans to vertebrates.
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Kondo-Okamoto, Noriko, Kentaro Ohkuni, Katsumi Kitagawa, J. Michael McCaffery, Janet M. Shaw, and Koji Okamoto. "The Novel F-Box Protein Mfb1p Regulates Mitochondrial Connectivity and Exhibits Asymmetric Localization in Yeast." Molecular Biology of the Cell 17, no. 9 (September 2006): 3756–67. http://dx.doi.org/10.1091/mbc.e06-02-0145.
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Although it is clear that mitochondrial morphogenesis is a complex process involving multiple proteins in eukaryotic cells, little is known about regulatory molecules that modulate mitochondrial network formation. Here, we report the identification of a new yeast mitochondrial morphology gene called MFB1 (YDR219C). MFB1 encodes an F-box protein family member, many of which function in Skp1-Cdc53/Cullin-F-box protein (SCF) ubiquitin ligase complexes. F-box proteins also act in non-SCF complexes whose functions are not well understood. Although cells lacking Mfb1p contain abnormally short mitochondrial tubules, Mfb1p is not essential for known pathways that determine mitochondrial morphology and dynamics. Mfb1p is peripherally associated with the mitochondrial surface. Coimmunoprecipitation assays reveal that Mfb1p interacts with Skp1p in an F-box–dependent manner. However, Mfb1p does not coimmunoprecipitate with Cdc53p. The F-box motif is not essential for Mfb1p-mediated mitochondrial network formation. These observations suggest that Mfb1p acts in a complex lacking Cdc53p required for mitochondrial morphogenesis. During budding, Mfb1p asymmetrically localizes to mother cell mitochondria. By contrast, Skp1p accumulates in the daughter cell cytoplasm. Mfb1p mother cell-specific asymmetry depends on the F-box motif, suggesting that Skp1p down-regulates Mfb1p mitochondrial association in buds. We propose that Mfb1p operates in a novel pathway regulating mitochondrial tubular connectivity.
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Rodrigues, Célia F., and Lucia Černáková. "Farnesol and Tyrosol: Secondary Metabolites with a Crucial quorum-sensing Role in Candida Biofilm Development." Genes 11, no. 4 (April 18, 2020): 444. http://dx.doi.org/10.3390/genes11040444.
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When living in biological and interactive communities, microorganisms use quorum-sensing mechanisms for their communication. According to cell density, bacteria and fungi can produce signaling molecules (e.g., secondary metabolites), which participate, for example, in the regulation of gene expression and coordination of collective behavior in their natural niche. The existence of these secondary metabolites plays a main role in competence, colonization of host tissues and surfaces, morphogenesis, and biofilm development. Therefore, for the design of new antibacterials or antifungals and understanding on how these mechanisms occur, to inhibit the secretion of quorum-sensing (e.g., farnesol and tyrosol) molecules leading the progress of microbial infections seems to be an interesting option. In yeasts, farnesol has a main role in the morphological transition, inhibiting hyphae production in a concentration-dependent manner, while tyrosol has a contrary function, stimulating transition from spherical cells to germ tube form. It is beyond doubt that secretion of both molecules by fungi has not been fully described, but specific meaning for their existence has been found. This brief review summarizes the important function of these two compounds as signaling chemicals participating mainly in Candida morphogenesis and regulatory mechanisms.
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Hashimoto, K., H. Fujimoto, and N. Nakatsuji. "An ECM substratum allows mouse mesodermal cells isolated from the primitive streak to exhibit motility similar to that inside the embryo and reveals a deficiency in the T/T mutant cells." Development 100, no. 4 (August 1, 1987): 587–98. http://dx.doi.org/10.1242/dev.100.4.587.
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The mesodermal cell layer is created by ingression and migration of the cells from the primitive streak region in mouse embryos on day 7 of pregnancy. In order to study the mechanisms of mesodermal cell migration during development, the mesodermal cells isolated from the primitive streak were cultured on various substrata, and cell behaviour and motility were analysed with a time-lapse video system. The mesodermal cells on the surface of extracellular matrix (ECM)-coated dishes (ECM produced by bovine corneal endothelial cells) showed extensive migration at a mean rate of approx. 50 micron h-1. They also showed frequent cell division and exhibited contact paralysis of lamellipodia and contact inhibition of movement. On plastic or glass surfaces, however, the mesodermal cells became more flattened and less motile (approx. 20–30 micron h-1). Cell shape and mean rate of movement on the ECM were very similar to those in situ, as investigated in a previous study (Nakatsuji, Snow & Wylie, 1986). Therefore, this culture condition could provide a useful experimental system for analysing the cellular basis of normal and abnormal morphogenetic movements in mouse embryos. Employing such a culture system, we studied motility of the mesodermal cells from embryos homozygous for Brachyury (T) mutation, which are lethal at the midgestation stage in utero. Histological observations have suggested that anomalous morphogenesis of the T/T embryos may be brought about by defects in migration of the mesodermal cells derived from the primitive streak. When mesodermal cells from the primitive streak of the T/T mutant embryos on days 8–9 were cultured on the ECM substratum, mean rate of cell migration was significantly reduced compared to cells from normal embryos. Results support the idea of retarded migration by the mutant mesodermal cells as an important factor causing abnormalities in morphogenesis.
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Sonnenberg, E., D. Meyer, K. M. Weidner, and C. Birchmeier. "Scatter factor/hepatocyte growth factor and its receptor, the c-met tyrosine kinase, can mediate a signal exchange between mesenchyme and epithelia during mouse development." Journal of Cell Biology 123, no. 1 (October 1, 1993): 223–35. http://dx.doi.org/10.1083/jcb.123.1.223.
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Scatter factor/hepatocyte growth factor (SF/HGF) has potent motogenic, mitogenic, and morphogenetic activities on epithelial cells in vitro. The cell surface receptor for this factor was recently identified: it is the product of the c-met protooncogene, a receptor-type tyrosine kinase. We report here the novel and distinct expression patterns of SF/HGF and its receptor during mouse development, which was determined by a combination of in situ hybridization and RNase protection experiments. Predominantly, we detect transcripts of c-met in epithelial cells of various developing organs, whereas the ligand is expressed in distinct mesenchymal cells in close vicinity. In addition, transient SF/HGF and c-met expression is found at certain sites of muscle formation; transient expression of the c-met gene is also detected in developing motoneurons. SF/HGF and the c-met receptor might thus play multiple developmental roles, most notably, mediate a signal given by mesenchyme and received by epithelial. Mesenchymal signals are known to govern differentiation and morphogenesis of many epithelia, but the molecular nature of the signals has remained poorly understood. Therefore, the known biological activities of SF/HGF in vitro and the embryonal expression pattern reported here indicate that this mesenchymal factor can transmit morphogenetic signals in epithelial development and suggest a molecular mechanism for mesenchymal epithelial interactions.
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Price, Kirsten D., and Richard Losick. "A Four-Dimensional View of Assembly of a Morphogenetic Protein during Sporulation in Bacillus subtilis." Journal of Bacteriology 181, no. 3 (February 1, 1999): 781–90. http://dx.doi.org/10.1128/jb.181.3.781-790.1999.
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ABSTRACT We report the use of a fusion to the green fluorescent protein to visualize the assembly of the morphogenetic protein SpoIVA around the developing forespore during the process of sporulation in the bacteriumBacillus subtilis. Using a deconvolution algorithm to process digitally-collected optical sections, we show that SpoIVA, which is synthesized in the mother cell chamber of the sporangium, assembled into a spherical shell around the outer surface of the forespore. Time-lapse fluorescence microscopy showed that this assembly process commenced at the time of polar division and seemed to continue after engulfment of the forespore was complete. SpoIVA remained present throughout the late stages of morphogenesis and was present as a component of the fully mature spore. Evidence indicates that assembly of SpoIVA depended on the extreme C-terminal region of the protein and an additional region that directly or indirectly facilitated interaction among SpoIVA molecules. The N- and C-terminal regions of SpoIVA, including the extreme C terminus, are highly similar to the corresponding regions of the homologous protein from the distantly related endospore-forming bacterium Clostridium acetobutylicum, attesting to their importance in the function of the protein. Finally, we show that proper localization of SpoIVA required the expression of one or more genes which, likespoIVA, are under the control of the mother cell transcription factor ςE. One such gene wasspoVM, whose product was required for efficient targeting of SpoIVA to the outer surface of the forespore.
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Andrews, John H., Robin F. Harris, Russell N. Spear, Gee W. Lau, and Erik V. Nordheim. "Morphogenesis and adhesion of Aureobasidium pullulans." Canadian Journal of Microbiology 40, no. 1 (January 1, 1994): 6–17. http://dx.doi.org/10.1139/m94-002.
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Two strains of the dimorphic fungus Aureobasidium pullulans were grown in liquid and on solid media varying in carbon and nitrogen content, and on leaf surfaces. Hyphae were observed in all systems but comprised a very low proportion (often below quantitative detection) of the total biomass. In liquid media, hyphae were found sparsely and only in the wash-zone on walls of the culture flasks. Yeast phase growth (blastospores) occurred in pH-buffered media that were nutrient balanced, or continuously carbon-limited (fed-batch culture), or carbon-exhausted (batch culture). Blastospores exposed to conditions with limited nitrogen but sufficient organic carbon, or to acidified media, converted to swollen cells and chlamydospores. The latter morphotypes accumulated carbon internally as lipid granules, and then externally as capsular and soluble extracellular polysaccharide. They were cohesive and also adhered more strongly to cellulose membranes overlying agar media or to leaves than did blastospores. Pullulanase treatment diminished the capsules, cohesion, and adhesion. Addition of soluble extracellular polysaccharide to blastospores enhanced their adhesion to leaves. We conclude that extracellular polysaccharide can play a role in adhesion of A. pullulans.Key words: phylloplane, leaf surface, epiphytic growth, extracellular polysaccharide, cell attachment.
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Holloway, David M., and Lionel G. Harrison. "Algal morphogenesis: modelling interspecific variation in Micrasterias with reaction–diffusion patterned catalysis of cell surface growth." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 354, no. 1382 (February 28, 1999): 417–33. http://dx.doi.org/10.1098/rstb.1999.0395.
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Semi–cell morphogenesis in unicellular desmid algae of the genus Micrasterias generates a stellar shape by repeated dichotomous branching of growing tips of the cell surface. The numerous species of the genus display variations of the branching pattern that differ markedly in number of branchings, lobe width and lobe length. We have modelled this morphogenesis, following previous work by D. M. Harrison and M. Kolár (1988), on the assumptions that patterning occurs by chemical reaction–diffusion activity within the plasma membrane, leading to morphological expression by patterned catalysis of the extension of the cell surface. The latter has been simulated in simplified form by two–dimensional computations. Our results indicate that for generation of repeated branchings and for the control of diverse species–specific shapes, the loss of patterning activity and of rapid growth in regions separating the active growing tips is an essential feature. We believe this conclusion to be much more general than the specific details of our model. We discuss the limitations of the model especially in terms of what extra features might be addressed in three–dimensional computation.
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Kobayashi, Takashi, Theerawut Chanmee, and Naoki Itano. "Hyaluronan: Metabolism and Function." Biomolecules 10, no. 11 (November 7, 2020): 1525. http://dx.doi.org/10.3390/biom10111525.
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As a major polysaccharide component of the extracellular matrix, hyaluronan plays essential roles in the organization of tissue architecture and the regulation of cellular functions, such as cell proliferation and migration, through interactions with cell-surface receptors and binding molecules. Metabolic pathways for biosynthesis and degradation tightly control the turnover rate, concentration, and molecular size of hyaluronan in tissues. Despite the relatively simple chemical composition of this polysaccharide, its wide range of molecular weights mediate diverse functions that depend on molecular size and tissue concentration. Genetic engineering and pharmacological approaches have demonstrated close associations between hyaluronan metabolism and functions in many physiological and pathological events, including morphogenesis, wound healing, and inflammation. Moreover, emerging evidence has suggested that the accumulation of hyaluronan extracellular matrix and fragments due to the altered expression of hyaluronan synthases and hyaluronidases potentiates cancer development and progression by remodeling the tumor microenvironment. In addition to the well-known functions exerted by extracellular hyaluronan, recent metabolomic approaches have also revealed that its synthesis can regulate cellular functions via the reprogramming of cellular metabolism. This review highlights the current advances in knowledge on the biosynthesis and catabolism of hyaluronan and describes the diverse functions associated with hyaluronan metabolism.
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Ethell, Iryna M., Kazuki Hagihara, Yoshiaki Miura, Fumitoshi Irie, and Yu Yamaguchi. "Synbindin, a Novel Syndecan-2–Binding Protein in Neuronal Dendritic Spines." Journal of Cell Biology 151, no. 1 (October 2, 2000): 53–68. http://dx.doi.org/10.1083/jcb.151.1.53.
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Dendritic spines are small protrusions on the surface of dendrites that receive the vast majority of excitatory synapses. We previously showed that the cell-surface heparan sulfate proteoglycan syndecan-2 induces spine formation upon transfection into hippocampal neurons. This effect requires the COOH-terminal EFYA sequence of syndecan-2, suggesting that cytoplasmic molecules interacting with this sequence play a critical role in spine morphogenesis. Here, we report a novel protein that binds to the EFYA motif of syndecan-2. This protein, named synbindin, is expressed by neurons in a pattern similar to that of syndecan-2, and colocalizes with syndecan-2 in the spines of cultured hippocampal neurons. In transfected hippocampal neurons, synbindin undergoes syndecan-2–dependent clustering. Synbindin is structurally related to yeast proteins known to be involved in vesicle transport. Immunoelectron microscopy localized synbindin on postsynaptic membranes and intracellular vesicles within dendrites, suggesting a role in postsynaptic membrane trafficking. Synbindin coimmunoprecipitates with syndecan-2 from synaptic membrane fractions. Our results show that synbindin is a physiological syndecan-2 ligand on dendritic spines. We suggest that syndecan-2 induces spine formation by recruiting intracellular vesicles toward postsynaptic sites through the interaction with synbindin.
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Barreiro, Olga, María Yáñez-Mó, Juan M. Serrador, María C. Montoya, Miguel Vicente-Manzanares, Reyes Tejedor, Heinz Furthmayr, and Francisco Sánchez-Madrid. "Dynamic interaction of VCAM-1 and ICAM-1 with moesin and ezrin in a novel endothelial docking structure for adherent leukocytes." Journal of Cell Biology 157, no. 7 (June 24, 2002): 1233–45. http://dx.doi.org/10.1083/jcb.200112126.
Full textAbstract:
Ezrin, radixin, and moesin (ERM) regulate cortical morphogenesis and cell adhesion by connecting membrane adhesion receptors to the actin-based cytoskeleton. We have studied the interaction of moesin and ezrin with the vascular cell adhesion molecule (VCAM)-1 during leukocyte adhesion and transendothelial migration (TEM). VCAM-1 interacted directly with moesin and ezrin in vitro, and all of these molecules colocalized at the apical surface of endothelium. Dynamic assessment of this interaction in living cells showed that both VCAM-1 and moesin were involved in lymphoblast adhesion and spreading on the endothelium, whereas only moesin participated in TEM, following the same distribution pattern as ICAM-1. During leukocyte adhesion in static or under flow conditions, VCAM-1, ICAM-1, and activated moesin and ezrin clustered in an endothelial actin-rich docking structure that anchored and partially embraced the leukocyte containing other cytoskeletal components such as α-actinin, vinculin, and VASP. Phosphoinositides and the Rho/p160 ROCK pathway, which participate in the activation of ERM proteins, were involved in the generation and maintenance of the anchoring structure. These results provide the first characterization of an endothelial docking structure that plays a key role in the firm adhesion of leukocytes to the endothelium during inflammation.
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Chen, Zhihua, John E. Morales, Naze Avci, Paola A. Guerrero, Ganesh Rao, Je Hoon Seo, and Joseph H. McCarty. "The vascular endothelial cell-expressed prion protein doppel promotes angiogenesis and blood-brain barrier development." Development 147, no. 18 (September 7, 2020): dev193094. http://dx.doi.org/10.1242/dev.193094.
Full textAbstract:
ABSTRACTThe central nervous system (CNS) contains a complex network of blood vessels that promote normal tissue development and physiology. Abnormal control of blood vessel morphogenesis and maturation is linked to the pathogenesis of various neurodevelopmental diseases. The CNS-specific genes that regulate blood vessel morphogenesis in development and disease remain largely unknown. Here, we have characterized functions for the gene encoding prion protein 2 (Prnd) in CNS blood vessel development and physiology. Prnd encodes the glycosylphosphatidylinositol (GPI)-linked protein doppel, which is expressed on the surface of angiogenic vascular endothelial cells, but is absent in quiescent endothelial cells of the adult CNS. During CNS vascular development, doppel interacts with receptor tyrosine kinases and activates cytoplasmic signaling pathways involved in endothelial cell survival, metabolism and migration. Analysis of mice genetically null for Prnd revealed impaired CNS blood vessel morphogenesis and associated endothelial cell sprouting defects. Prnd−/− mice also displayed defects in endothelial barrier integrity. Collectively, these data reveal novel mechanisms underlying doppel control of angiogenesis in the developing CNS, and may provide new insights about dysfunctional pathways that cause vascular-related CNS disorders.
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Brower, D. L., T. A. Bunch, L. Mukai, T. E. Adamson, M. Wehrli, S. Lam, E. Friedlander, C. E. Roote, and S. Zusman. "Nonequivalent requirements for PS1 and PS2 integrin at cell attachments in Drosophila: genetic analysis of the alpha PS1 integrin subunit." Development 121, no. 5 (May 1, 1995): 1311–20. http://dx.doi.org/10.1242/dev.121.5.1311.
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We report on the generation and phenotype of mutant alleles of multiple edematous wings (mew), the gene encoding the alpha PS1 subunit of the PS1 integrin of Drosophila. None of the six alleles examined makes detectable protein, and one allele results from a chromosome break near the middle of the translated sequence, so we are confident that we have described the null phenotype. In contrast to if (alpha PS2) and mys (beta PS) mutants, most mutant mew embryos hatch, to die as larvae. Mutant mew embryos display abnormal gut morphogenesis but, unlike mys or if embryos, there is no evidence of defects in the somatic muscles. Thus, the complementary distributions of PS1 (alpha PS1 beta PS) and PS2 (alpha PS2 beta PS) integrin on tendon cells and muscle, respectively, do not reflect equivalent requirements at the myotendinous junction. Dorsal herniation, characteristic of the mys lethal phenotype, is not observed in mew or in mew if embryos. Clonal analysis experiments indicate that eye morphogenesis is disrupted in mew clones, but if clones in the eye are relatively normal in morphology. Adult wings display blisters around large dorsal but not ventral mew clones. In contrast to dorsal mys clones, small mew patches do not necessarily display morphogenetic abnormalities. Thus, another integrin in addition to PS1 appears to function on the dorsal wing surface.
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Fukushi, Jun-ichi, Irwan T. Makagiansar, and William B. Stallcup. "NG2 Proteoglycan Promotes Endothelial Cell Motility and Angiogenesis via Engagement of Galectin-3 and α3β1 Integrin." Molecular Biology of the Cell 15, no. 8 (August 2004): 3580–90. http://dx.doi.org/10.1091/mbc.e04-03-0236.
Full textAbstract:
The NG2 proteoglycan is expressed by microvascular pericytes in newly formed blood vessels. We have used in vitro and in vivo models to investigate the role of NG2 in cross-talk between pericytes and endothelial cells (EC). Binding of soluble NG2 to the EC surface induces cell motility and multicellular network formation in vitro and stimulates corneal angiogenesis in vivo. Biochemical data demonstrate the involvement of both galectin-3 and α3β1 integrin in the EC response to NG2 and show that NG2, galectin-3, and α3β1 form a complex on the cell surface. Transmembrane signaling via α3β1 is responsible for EC motility and morphogenesis in this system. Galectin-3–dependent oligomerization may potentiate NG2-mediated activation of α3β1. In conjunction with recent studies demonstrating the early involvement of pericytes in angiogenesis, these data suggest that pericyte-derived NG2 is an important factor in promoting EC migration and morphogenesis during the early stages of neovascularization.
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Chuang, Jen-Zen, Szu-Yi Chou, and Ching-Hwa Sung. "Chloride Intracellular Channel 4 Is Critical for the Epithelial Morphogenesis of RPE Cells and Retinal Attachment." Molecular Biology of the Cell 21, no. 17 (September 2010): 3017–28. http://dx.doi.org/10.1091/mbc.e09-10-0907.
Full textAbstract:
Retinal detachment is a sight-threatening condition. The molecular mechanism underlying the adhesion between the RPE and photoreceptors is poorly understood because the intimate interactions between these two cell types are impossible to model and study in vitro. In this article, we show that chloride intracellular channel 4 (CLIC4) is enriched at apical RPE microvilli, which are interdigitated with the photoreceptor outer segment. We used a novel plasmid-based transfection method to cell-autonomously suppress CLIC4 in RPE in situ. CLIC4 silenced RPE cells exhibited a significant loss of apical microvilli and basal infoldings, reduced retinal adhesion, and epithelial-mesenchymal transition. Ectopically expressing ezrin failed to rescue the morphological changes exerted by CLIC4 silencing. Neural retinas adjacent to the CLIC4-suppressed RPE cells display severe dysplasia. Finally, a high level of aquaporin 1 unexpectedly appeared at the apical surfaces of CLIC4-suppressed RPE cells, together with a concomitant loss of basal surface expression of monocarboxylate transporter MCT3. Our results suggested that CLIC4 plays an important role in RPE-photoreceptor adhesion, perhaps by modulating the activity of cell surface channels/transporters. We propose that these changes may be attributable to subretinal fluid accumulation in our novel retinal detachment animal model.
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Vainio, S., M. Jalkanen, and I. Thesleff. "Syndecan and tenascin expression is induced by epithelial-mesenchymal interactions in embryonic tooth mesenchyme." Journal of Cell Biology 108, no. 5 (May 1, 1989): 1945–53. http://dx.doi.org/10.1083/jcb.108.5.1945.
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Morphogenesis of embryonic organs is regulated by epithelial-mesenchymal interactions associating with changes in the extracellular matrix (ECM). The response of the cells to the changes in the ECM must involve integral cell surface molecules that recognize their matrix ligand and initiate transmission of signal intracellularly. We have studied the expression of the cell surface proteoglycan, syndecan, which is a matrix receptor for epithelial cells (Saunders, S., M. Jalkanen, S. O'Farrell, and M. Bernfield. J. Cell Biol. In press.), and the matrix glycoprotein, tenascin, which has been proposed to be involved in epithelial-mesenchymal interactions (Chiquet-Ehrismann, R., E. J. Mackie, C. A. Pearson, and T. Sakakura. 1986. Cell. 47:131-139) in experimental tissue recombinations of dental epithelium and mesenchyme. Our earlier studies have shown that in mouse embryos both syndecan and tenascin are intensely expressed in the condensing dental mesenchyme surrounding the epithelial bud (Thesleff, I., M. Jalkanen, S. Vainio, and M. Bernfield. 1988. Dev. Biol. 129:565-572; Thesleff, I., E. Mackie, S. Vainio, and R. Chiquet-Ehrismann. 1987. Development. 101:289-296). Analysis of rat-mouse tissue recombinants by a monoclonal antibody against the murine syndecan showed that the presumptive dental epithelium induces the expression of syndecan in the underlying mesenchyme. The expression of tenascin was induced in the dental mesenchyme in the same area as syndecan. The syndecan and tenascin positive areas increased with time of epithelial-mesenchymal contact. Other ECM molecules, laminin, type III collagen, and fibronectin, did not show a staining pattern similar to that of syndecan and tenascin. Oral epithelium from older embryos had lost its ability to induce syndecan expression but the presumptive dental epithelium induced syndecan expression even in oral mesenchyme of older embryos. Our results indicate that the expression of syndecan and tenascin in the tooth mesenchyme is regulated by epithelial-mesenchymal interactions. Because of their early appearance, syndecan and tenascin may be used to study the molecular regulation of this interaction. The similar distribution patterns of syndecan and tenascin in vivo and in vitro and their early appearance as a result of epithelial-mesenchymal interaction suggest that these molecules may be involved in the condensation and differentiation of dental mesenchymal cells.