Journal articles: 'Actin'

1

Roberts, Thomas M., and Murray Stewart. "Acting like Actin." Journal of Cell Biology 149, no. 1 (April 3, 2000): 7–12. http://dx.doi.org/10.1083/jcb.149.1.7.

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2

Vinson, V. "Acting Like Actin." Science 330, no. 6009 (December 2, 2010): 1289. http://dx.doi.org/10.1126/science.330.6009.1289-b.

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3

Marx, Vivien. "Actin in action." Nature Methods 20, no. 2 (February 2023): 178–82. http://dx.doi.org/10.1038/s41592-022-01762-2.

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4

Muscat, G. E., T. A. Gustafson, and L. Kedes. "A common factor regulates skeletal and cardiac alpha-actin gene transcription in muscle." Molecular and Cellular Biology 8, no. 10 (October 1988): 4120–33. http://dx.doi.org/10.1128/mcb.8.10.4120-4133.1988.

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The skeletal and cardiac alpha-actin genes are coexpressed in muscle development but exhibit distinctive tissue-specific patterns of expression. We used an in vivo competition assay and an in vitro electrophoretic mobility shift assay to demonstrate that both genes interact with a common trans-acting factor(s). However, there was at least one gene-specific cis-acting sequence in the skeletal alpha-actin gene that interacted with a trans-acting factor which was not rate limiting in the expression of the cardiac alpha-actin gene. The common factor(s) interacted with several cis-acting regions that corresponded to sequences that are required for the transcriptional modulation of these sarcomeric alpha-actin genes in muscle cells. These regulatory regions contained the sequence motif CC(A + T-rich)6GG, which is known as a CArG box. Results of in vivo competition assays demonstrated that the factor(s) bound by the skeletal alpha-actin gene is also essential for the maximal activity of the cardiac alpha-actin, simian virus 40 (SV40), alpha 2(I)-collagen, and the beta-actin promoters in muscle cells. In contrast, fibroblastic cells contained functionally distinct transcription factor(s) that were used by the SV40 enhancer but that did not interact with the sarcomeric alpha-actin cis-acting sequences. The existence of functionally different factors in these cell types may explain the myogenic specificity of these sarcomeric alpha-actin genes. Results of in vitro studies suggested that both the sarcomeric alpha-actin genes interact with the CArG box-binding factor CBF and that the skeletal alpha-actin promoter contains multiple CBF-binding sites. In contrast, CBF did not interact in vitro with a classical CAAT box, the SV40 enhancer, or a linker scanner mutation of an alpha-actin CArG box. Furthermore, methylation interference and DNase I footprinting assays demonstrated the precise sites of interaction of CBF with three CArG motifs at positions -98, -179, and -225 in the human skeletal alpha-actin gene.

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5

Muscat, G. E., T. A. Gustafson, and L. Kedes. "A common factor regulates skeletal and cardiac alpha-actin gene transcription in muscle." Molecular and Cellular Biology 8, no. 10 (October 1988): 4120–33. http://dx.doi.org/10.1128/mcb.8.10.4120.

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The skeletal and cardiac alpha-actin genes are coexpressed in muscle development but exhibit distinctive tissue-specific patterns of expression. We used an in vivo competition assay and an in vitro electrophoretic mobility shift assay to demonstrate that both genes interact with a common trans-acting factor(s). However, there was at least one gene-specific cis-acting sequence in the skeletal alpha-actin gene that interacted with a trans-acting factor which was not rate limiting in the expression of the cardiac alpha-actin gene. The common factor(s) interacted with several cis-acting regions that corresponded to sequences that are required for the transcriptional modulation of these sarcomeric alpha-actin genes in muscle cells. These regulatory regions contained the sequence motif CC(A + T-rich)6GG, which is known as a CArG box. Results of in vivo competition assays demonstrated that the factor(s) bound by the skeletal alpha-actin gene is also essential for the maximal activity of the cardiac alpha-actin, simian virus 40 (SV40), alpha 2(I)-collagen, and the beta-actin promoters in muscle cells. In contrast, fibroblastic cells contained functionally distinct transcription factor(s) that were used by the SV40 enhancer but that did not interact with the sarcomeric alpha-actin cis-acting sequences. The existence of functionally different factors in these cell types may explain the myogenic specificity of these sarcomeric alpha-actin genes. Results of in vitro studies suggested that both the sarcomeric alpha-actin genes interact with the CArG box-binding factor CBF and that the skeletal alpha-actin promoter contains multiple CBF-binding sites. In contrast, CBF did not interact in vitro with a classical CAAT box, the SV40 enhancer, or a linker scanner mutation of an alpha-actin CArG box. Furthermore, methylation interference and DNase I footprinting assays demonstrated the precise sites of interaction of CBF with three CArG motifs at positions -98, -179, and -225 in the human skeletal alpha-actin gene.

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6

P, RAGHAVENDRA K., RAKESH KUMAR, JOY DAS, SANTOSH H. B, SACHIN A. MORE, RAMAKRISHNA N, SHILPA G. CHAWLA, SANDHYA KRANTHI, and KESHAV RAJ KRANTHI. "Quantitative real-time PCR based evaluation and validation of reference genes in Gossypium arboreum." Indian Journal of Agricultural Sciences 90, no. 1 (March 2, 2020): 40–47. http://dx.doi.org/10.56093/ijas.v90i1.98527.

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Estimation of gene expression levels plays a crucial role in understanding the function of the target gene(s). Intersample variance in gene expression can be more precisely measured if transcripts levels are accurately normalized. Normalization is pre-requisite step prior to the determination of candidate gene expression by qPCR. In this study conducted at ICAR-Central Institute for Cotton Research, Nagpur during 2015–16, six candidate reference genes, viz. actin4 (ACT4), actin7(ACT7), RNA Helicase (RNAH), Serine/threonine-protein phosphatase PP2A-1(PP2A1), ubiquitin7 (UBQ7) and α tubulin (αTUB) were systematically analysed for their expression patterns in different tissues pertaining to three development stages of cotton namely seedling, early reproductive and fiber development. The study has identified actin-4/actin-7/ubiquitin-7 as the most ideal reference genes for fiber development stages whereas actin-4/ ubiquitin-7 and actin-7/RNA helicases for seedling and early reproductive development stages, respectively. Validation of identified reference genes for relative expression analysis of Gacobl9, a COBRA-like protein, demonstrated their usefulness in qPCR analysis in Gossypium arboreum.

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7

Hurtley, Stella M. "Parasite actin in action." Science 366, no. 6465 (October 31, 2019): 584.6–585. http://dx.doi.org/10.1126/science.366.6465.584-f.

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8

Hurtley, S. M. "Nuclear Actin in Action." Science Signaling 6, no. 276 (May 21, 2013): ec116-ec116. http://dx.doi.org/10.1126/scisignal.2004335.

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9

Geitmann, Anja. "Actuators Acting without Actin." Cell 166, no. 1 (June 2016): 15–17. http://dx.doi.org/10.1016/j.cell.2016.06.030.

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10

WINDER, Steven J., Thomas JESS, and Kathryn R. AYSCOUGH. "SCP1 encodes an actin-bundling protein in yeast." Biochemical Journal 375, no. 2 (October 15, 2003): 287–95. http://dx.doi.org/10.1042/bj20030796.

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The association of F-actin (filamentous actin) with a large number of binding proteins is essential for cellular function. Actin-binding proteins control the dynamics of actin filaments, nucleate new filaments and facilitate formation of higher-order structures such as actin bundles. The yeast gene SCP1 encodes a small protein with significant homology to mammalian SM22/transgelin. We have investigated the role of Scp1p in budding yeast to probe the fundamental role of this family of proteins. Here, we demonstrate that Scp1p binds to F-actin and induces the formation of tight F-actin bundles in vitro. Deletion of SCP1 in yeast lacking the actin-bundling protein, fimbrin (Sac6p), exacerbates the disrupted actin phenotype and enhances latrunculin-A sensitivity. Furthermore, Scp1p co-localizes with actin in cortical patches and its localization is lost in the presence of latrunculin-A. Our data support a role for Scp1p in bundling actin filaments and, in concert with Sac6p, acting as a second actin-bundling activity crucial to the stability of the yeast actin cytoskeleton.

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11

Kuběnová, Lenka, Tomáš Takáč, Jozef Šamaj, and Miroslav Ovečka. "Single Amino Acid Exchange in ACTIN2 Confers Increased Tolerance to Oxidative Stress in Arabidopsis der1–3 Mutant." International Journal of Molecular Sciences 22, no. 4 (February 13, 2021): 1879. http://dx.doi.org/10.3390/ijms22041879.

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Single-point mutation in the ACTIN2 gene of the der1–3 mutant revealed that ACTIN2 is an essential actin isovariant required for root hair tip growth, and leads to shorter, thinner and more randomly oriented actin filaments in comparison to the wild-type C24 genotype. The actin cytoskeleton has been linked to plant defense against oxidative stress, but it is not clear how altered structural organization and dynamics of actin filaments may help plants to cope with oxidative stress. In this study, we characterized root growth, plant biomass, actin organization and antioxidant activity of the der1–3 mutant under oxidative stress induced by paraquat and H2O2. Under these conditions, plant growth was better in the der1–3 mutant, while the actin cytoskeleton in the der1–3 carrying pro35S::GFP:FABD2 construct showed a lower bundling rate and higher dynamicity. Biochemical analyses documented a lower degree of lipid peroxidation, and an elevated capacity to decompose superoxide and hydrogen peroxide. These results support the view that the der1–3 mutant is more resistant to oxidative stress. We propose that alterations in the actin cytoskeleton, increased sensitivity of ACTIN to reducing agent dithiothreitol (DTT), along with the increased capacity to decompose reactive oxygen species encourage the enhanced tolerance of this mutant against oxidative stress.

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12

Huang, Dichun. "Young and Senescent Cells: Distinct Nuclear F-actin Patterns Upon Latrunculin B Induction." International Journal of Biology and Life Sciences 2, no. 3 (May 22, 2023): 12–15. http://dx.doi.org/10.54097/ijbls.v2i3.8644.

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Both cellular senescence and cytoskeleton are involved in the formation of many diseases and cell signaling pathways. Although recent studies have shown that F-actin is involved in DNA damage repair, chromatin decompression, gene transcription regulation, and cell fate determination. But studies on F-actin and aging are still absence. It is unclear whether nuclear F-actin is present during cellular senescence. Here, by confocal optical sectioning and time-lapse imaging, we found acitn chrommobody-TagGFP2-NLS shows the beneficial on investigating senescent human fibroblast IMR-90 cells. To induce the nuclear F-actin assembly in single cell, we uesd Latrunculin B (latB) which a cytoplasmic F-actin polymerization inhibitor. It is currently unknown whether the nuclear F-actin cytoskeleton in young and senescent cells responds differently to latB treatment. Here, latB application induces distinct nuclear F-actin patterns and dynamics in young and senescent cells. Thus, after analyzing the results of actin dynamic we demonstrate a diverse effect of latB on the nuclear F-actin cytoskeleton in young and senescent cells.

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13

Egea, Gustavo, Carla Serra-Peinado, Laia Salcedo-Sicilia, and Enric Gutiérrez-Martínez. "Actin acting at the Golgi." Histochemistry and Cell Biology 140, no. 3 (June 27, 2013): 347–60. http://dx.doi.org/10.1007/s00418-013-1115-8.

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14

JAMES, Marianne F., Nitasha MANCHANDA, Charo GONZALEZ-AGOSTI, John H. HARTWIG, and Vijaya RAMESH. "The neurofibromatosis 2 protein product merlin selectively binds F-actin but not G-actin, and stabilizes the filaments through a lateral association." Biochemical Journal 356, no. 2 (May 24, 2001): 377–86. http://dx.doi.org/10.1042/bj3560377.

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The neurofibromatosis 2 protein product merlin, named for its relatedness to the ezrin, radixin and moesin (ERM) family of proteins, is a tumour suppressor whose absence results in the occurrence of multiple tumours of the nervous system, particularly schwannomas and meningiomas. Merlin's similarity to ERMs suggests that it might share functions, acting as a link between cytoskeletal components and the cell membrane. The N-terminus of merlin has strong sequence identity to the N-terminal actin-binding region of ezrin; here we describe in detail the merlin–actin interaction. Employing standard actin co-sedimentation assays, we have determined that merlin isoform 2 binds F-actin with an apparent binding constant of 3.6μM and a stoichiometry of 1mol of merlin per 11.5mol of actin in filaments at saturation. Further, solid-phase binding assays reveal that merlin isoforms 1 and 2 bind actin filaments differentially, suggesting that the intramolecular interactions in isoform 1 might hinder its ability to bind actin. However, merlin does not bind G-actin. Studies of actin filament dynamics show that merlin slows filament disassembly with no influence on the assembly rate, indicating that merlin binds along actin filament lengths. This conclusion is supported by electron microscopy, which demonstrates that merlin binds periodically along cytoskeletal actin filaments. Comparison of these findings with those reported for ERM proteins reveal a distinct role for merlin in actin filament dynamics.

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15

Mullins, R. Dyche, Joseph F. Kelleher, and Thomas D. Pollard. "Actin' like actin?" Trends in Cell Biology 6, no. 6 (June 1996): 208–12. http://dx.doi.org/10.1016/0962-8924(96)20017-0.

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16

Wei, Mian, Xiaoying Fan, Miao Ding, Ruifeng Li, Shipeng Shao, Yingping Hou, Shaoshuai Meng, Fuchou Tang, Cheng Li, and Yujie Sun. "Nuclear actin regulates inducible transcription by enhancing RNA polymerase II clustering." Science Advances 6, no. 16 (April 2020): eaay6515. http://dx.doi.org/10.1126/sciadv.aay6515.

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Gene expression in response to stimuli underlies many fundamental processes. However, how transcription is regulated under these scenarios is largely unknown. Here, we find a previously unknown role of nuclear actin in transcriptional regulation. The RNA-seq data reveal that nuclear actin is required for the serum-induced transcriptional program. Using super-resolution imaging, we found a remarkable enhancement of RNA polymerase II (Pol II) clustering upon serum stimulation, and this enhancement requires nuclear actin. Pol II clusters colocalized with the serum-response genes and nuclear actin filaments upon serum stimulation. Furthermore, N-WASP is required for serum-enhanced Pol II clustering. N-WASP phase-separated with Pol II and nuclear actin. In addition to serum stimulation, nuclear actin also enhanced Pol II clustering upon interferon-γ treatment. Together, our work unveils that nuclear actin promotes the formation of transcription factory on inducible genes, acting as a general mechanism underlying the rapid response to environmental cues.

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17

Chen, Yuejun, Feifei Wang, Hui Long, Ying Chen, Ziyan Wu, and Lan Ma. "GRK5 promotes F-actin bundling and targets bundles to membrane structures to control neuronal morphogenesis." Journal of Cell Biology 194, no. 6 (September 19, 2011): 905–20. http://dx.doi.org/10.1083/jcb.201104114.

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Neuronal morphogenesis requires extensive membrane remodeling and cytoskeleton dynamics. In this paper, we show that GRK5, a G protein–coupled receptor kinase, is critically involved in neurite outgrowth, dendrite branching, and spine morphogenesis through promotion of filopodial protrusion. Interestingly, GRK5 is not acting as a kinase but rather provides a key link between the plasma membrane and the actin cytoskeleton. GRK5 promoted filamentous actin (F-actin) bundling at the membranes of dynamic neuronal structures by interacting with both F-actin and phosphatidylinositol-4,5-bisphosphate. Moreover, separate domains of GRK5 mediated the coupling of actin cytoskeleton dynamics and membrane remodeling and were required for its effects on neuronal morphogenesis. Accordingly, GRK5 knockout mice exhibited immature spine morphology and deficient learning and memory. Our findings identify GRK5 as a critical mediator of dendritic development and suggest that coordinated actin cytoskeleton and membrane remodeling mediated by bifunctional actin-bundling and membrane-targeting molecules, such as GRK5, is crucial for proper neuronal morphogenesis and the establishment of functional neuronal circuitry.

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18

Vaduva, Gabriela, Nancy C. Martin, and Anita K. Hopper. "Actin-binding Verprolin Is a Polarity Development Protein Required for the Morphogenesis and Function of the Yeast Actin Cytoskeleton." Journal of Cell Biology 139, no. 7 (December 29, 1997): 1821–33. http://dx.doi.org/10.1083/jcb.139.7.1821.

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Yeast verprolin, encoded by VRP1, is implicated in cell growth, cytoskeletal organization, endocytosis and mitochondrial protein distribution and function. We show that verprolin is also required for bipolar bud-site selection. Previously we reported that additional actin suppresses the temperature-dependent growth defect caused by a mutation in VRP1. Here we show that additional actin suppresses all known defects caused by vrp1-1 and conclude that the defects relate to an abnormal cytoskeleton. Using the two-hybrid system, we show that verprolin binds actin. An actin-binding domain maps to the LKKAET hexapeptide located in the first 70 amino acids. A similar hexapeptide in other acting-binding proteins was previously shown to be necessary for actin-binding activity. The entire 70– amino acid motif is conserved in novel higher eukaryotic proteins that we predict to be actin-binding, and also in the actin-binding proteins, WASP and N-WASP. Verprolin-GFP in live cells has a cell cycle-dependent distribution similar to the actin cortical cytoskeleton. In fixed cells hemagglutinin-tagged Vrp1p often co-localizes with actin in cortical patches. However, disassembly of the actin cytoskeleton using Latrunculin-A does not alter verprolin's location, indicating that verprolin establishes and maintains its location independent of the actin cytoskeleton. Verprolin is a new member of the actin-binding protein family that serves as a polarity development protein, perhaps by anchoring actin. We speculate that the effects of verprolin upon the actin cytoskeleton might influence mitochondrial protein sorting/function via mRNA distribution.

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19

Schüler, Herwig, and Kai Matuschewski. "Plasmodium motility: actin not actin' like actin." Trends in Parasitology 22, no. 4 (April 2006): 146–47. http://dx.doi.org/10.1016/j.pt.2006.02.005.

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20

Le Moigne, Ronan, Frédéric Subra, Manale Karam, and Christian Auclair. "The β-carboline Harmine Induces Actin Dynamic Remodeling and Abrogates the Malignant Phenotype in Tumorigenic Cells." Cells 9, no. 5 (May 8, 2020): 1168. http://dx.doi.org/10.3390/cells9051168.

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Numerous studies have shown that alteration of actin remodeling plays a pivotal role in the regulation of morphologic and phenotypic changes leading to malignancy. In the present study, we searched for drugs that can regulate actin polymerization and reverse the malignant phenotype in cancer cells. We developed a cell-free high-throughput screening assay for the identification of compounds that induce the actin polymerization in vitro, by fluorescence anisotropy. Then, the potential of the hit compound to restore the actin cytoskeleton and reverse the malignant phenotype was checked in EWS-Fli1-transformed fibroblasts and in B16-F10 melanoma cells. A β-carboline extracted from Peganum harmala (i.e., harmine) is identified as a stimulator of actin polymerization through a mechanism independent of actin binding and requiring intracellular factors involved in a process that regulates actin kinetics. Treatment of malignant cells with non-cytotoxic concentrations of harmine induces the recovery of a non-malignant cell morphology accompanied by reorganization of the actin cytoskeleton, rescued cell–cell adhesion, inhibition of cell motility and loss of anchorage-independent growth. In conclusion, harmine induces the reversion of the malignant phenotype by a process involving the modulation of actin dynamics and is a potential anti-tumor agent acting principally through a non-cytotoxic process.

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21

Grandy, Carolin, Fabian Port, Jonas Pfeil, and Kay-Eberhard Gottschalk. "Influence of ROCK Pathway Manipulation on the Actin Cytoskeleton Height." Cells 11, no. 3 (January 26, 2022): 430. http://dx.doi.org/10.3390/cells11030430.

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The actin cytoskeleton with its dynamic properties serves as the driving force for the movement and division of cells and gives the cell shape and structure. Disorders in the actin cytoskeleton occur in many diseases. Deeper understanding of its regulation is essential in order to better understand these biochemical processes. In our study, we use metal-induced energy transfer (MIET) as a tool to quantitatively examine the rarely considered third dimension of the actin cytoskeleton with nanometer accuracy. In particular, we investigate the influence of different drugs acting on the ROCK pathway on the three-dimensional actin organization. We find that cells treated with inhibitors have a lower actin height to the substrate while treatment with a stimulator for the ROCK pathway increases the actin height to the substrate, while the height of the membrane remains unchanged. This reveals the precise tuning of adhesion and cytoskeleton tension, which leads to a rich three-dimensional structural behaviour of the actin cytoskeleton. This finetuning is differentially affected by either inhibition or stimulation. The high axial resolution shows the importance of the precise finetuning of the actin cytoskeleton and the disturbed regulation of the ROCK pathway has a significant impact on the actin behavior in the z dimension.

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22

Chitu, Violeta, Fiona J. Pixley, Frank Macaluso, Daniel R. Larson, John Condeelis, Yee-Guide Yeung, and E. Richard Stanley. "The PCH Family Member MAYP/PSTPIP2 Directly Regulates F-Actin Bundling and Enhances Filopodia Formation and Motility in Macrophages." Molecular Biology of the Cell 16, no. 6 (June 2005): 2947–59. http://dx.doi.org/10.1091/mbc.e04-10-0914.

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Macrophage actin-associated tyrosine phosphorylated protein (MAYP) belongs to the Pombe Cdc15 homology (PCH) family of proteins involved in the regulation of actin-based functions including cell adhesion and motility. In mouse macrophages, MAYP is tyrosine phosphorylated after activation of the colony-stimulating factor-1 receptor (CSF-1R), which also induces actin reorganization, membrane ruffling, cell spreading, polarization, and migration. Because MAYP associates with F-actin, we investigated the function of MAYP in regulating actin organization in macrophages. Overexpression of MAYP decreased CSF-1–induced membrane ruffling and increased filopodia formation, motility and CSF-1-mediated chemotaxis. The opposite phenotype was observed with reduced expression of MAYP, indicating that MAYP is a negative regulator of CSF-1–induced membrane ruffling and positively regulates formation of filopodia and directional migration. Overexpression of MAYP led to a reduction in total macrophage F-actin content but was associated with increased actin bundling. Consistent with this, purified MAYP bundled F-actin and regulated its turnover in vitro. In addition, MAYP colocalized with cortical and filopodial F-actin in vivo. Because filopodia are postulated to increase directional motility by acting as environmental sensors, the MAYP-stimulated increase in directional movement may be at least partly explained by enhancement of filopodia formation.

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23

Saarikangas, Juha, Hongxia Zhao, and Pekka Lappalainen. "Regulation of the Actin Cytoskeleton-Plasma Membrane Interplay by Phosphoinositides." Physiological Reviews 90, no. 1 (January 2010): 259–89. http://dx.doi.org/10.1152/physrev.00036.2009.

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The plasma membrane and the underlying cortical actin cytoskeleton undergo continuous dynamic interplay that is responsible for many essential aspects of cell physiology. Polymerization of actin filaments against cellular membranes provides the force for a number of cellular processes such as migration, morphogenesis, and endocytosis. Plasma membrane phosphoinositides (especially phosphatidylinositol bis- and trisphosphates) play a central role in regulating the organization and dynamics of the actin cytoskeleton by acting as platforms for protein recruitment, by triggering signaling cascades, and by directly regulating the activities of actin-binding proteins. Furthermore, a number of actin-associated proteins, such as BAR domain proteins, are capable of directly deforming phosphoinositide-rich membranes to induce plasma membrane protrusions or invaginations. Recent studies have also provided evidence that the actin cytoskeleton-plasma membrane interactions are misregulated in a number of pathological conditions such as cancer and during pathogen invasion. Here, we summarize the wealth of knowledge on how the cortical actin cytoskeleton is regulated by phosphoinositides during various cell biological processes. We also discuss the mechanisms by which interplay between actin dynamics and certain membrane deforming proteins regulate the morphology of the plasma membrane.

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Verma, Suzie, Siew Ping Han, Magdalene Michael, Guillermo A. Gomez, Zhe Yang, Rohan D. Teasdale, Aparna Ratheesh, Eva M. Kovacs, Radiya G. Ali, and Alpha S. Yap. "A WAVE2–Arp2/3 actin nucleator apparatus supports junctional tension at the epithelial zonula adherens." Molecular Biology of the Cell 23, no. 23 (December 2012): 4601–10. http://dx.doi.org/10.1091/mbc.e12-08-0574.

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The epithelial zonula adherens (ZA) is a specialized adhesive junction where actin dynamics and myosin-driven contractility coincide. The junctional cytoskeleton is enriched in myosin II, which generates contractile force to support junctional tension. It is also enriched in dynamic actin filaments, which are replenished by ongoing actin assembly. In this study we sought to pursue the relationship between actin assembly and junctional contractility. We demonstrate that WAVE2–Arp2/3 is a major nucleator of actin assembly at the ZA and likely acts in response to junctional Rac signaling. Furthermore, WAVE2–Arp2/3 is necessary for junctional integrity and contractile tension at the ZA. Maneuvers that disrupt the function of either WAVE2 or Arp2/3 reduced junctional tension and compromised the ability of cells to buffer side-to-side forces acting on the ZA. WAVE2–Arp2/3 disruption depleted junctions of both myosin IIA and IIB, suggesting that dynamic actin assembly may support junctional tension by facilitating the local recruitment of myosin.

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Cingolani, Lorenzo A., and Yukiko Goda. "Actin in action: the interplay between the actin cytoskeleton and synaptic efficacy." Nature Reviews Neuroscience 9, no. 5 (May 2008): 344–56. http://dx.doi.org/10.1038/nrn2373.

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Jégou, Antoine, and Guillaume Romet-Lemonne. "Mechanically tuning actin filaments to modulate the action of actin-binding proteins." Current Opinion in Cell Biology 68 (February 2021): 72–80. http://dx.doi.org/10.1016/j.ceb.2020.09.002.

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Alonso-Sanz, Ramón, and Andy Adamatzky. "Actin Automata with Memory." International Journal of Bifurcation and Chaos 26, no. 01 (January 2016): 1650019. http://dx.doi.org/10.1142/s021812741650019x.

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Actin is a globular protein which forms long polar filaments in eukaryotic. The actin filaments play the roles of cytoskeleton, motility units, information processing and learning. We model actin filament as a double chain of finite state machines, nodes, which take states “0” and “1”. The states are abstractions of absence and presence of a subthreshold charge on actin units corresponding to the nodes. All nodes update their state in parallel to discrete time. A node updates its current state depending on states of two closest neighbors in the node chain and two closest neighbors in the complementary chain. Previous models of actin automata consider momentary state transitions of nodes. We enrich the actin automata model by assuming that states of nodes depend not only on the current states of neighboring node but also on their past states. Thus, we assess the effect of memory of past states on the dynamics of acting automata. We demonstrate in computational experiments that memory slows down propagation of perturbations, decrease entropy of space-time patterns generated, transforms traveling localizations to stationary oscillators, and stationary oscillations to still patterns.

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Chiu, Tim Ting, Nish Patel, Alisa E. Shaw, James R. Bamburg, and Amira Klip. "Arp2/3- and Cofilin-coordinated Actin Dynamics Is Required for Insulin-mediated GLUT4 Translocation to the Surface of Muscle Cells." Molecular Biology of the Cell 21, no. 20 (October 15, 2010): 3529–39. http://dx.doi.org/10.1091/mbc.e10-04-0316.

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GLUT4 vesicles are actively recruited to the muscle cell surface upon insulin stimulation. Key to this process is Rac-dependent reorganization of filamentous actin beneath the plasma membrane, but the underlying molecular mechanisms have yet to be elucidated. Using L6 rat skeletal myoblasts stably expressing myc-tagged GLUT4, we found that Arp2/3, acting downstream of Rac GTPase, is responsible for the cortical actin polymerization evoked by insulin. siRNA-mediated silencing of either Arp3 or p34 subunits of the Arp2/3 complex abrogated actin remodeling and impaired GLUT4 translocation. Insulin also led to dephosphorylation of the actin-severing protein cofilin on Ser-3, mediated by the phosphatase slingshot. Cofilin dephosphorylation was prevented by strategies depolymerizing remodeled actin (latrunculin B or p34 silencing), suggesting that accumulation of polymerized actin drives severing to enact a dynamic actin cycling. Cofilin knockdown via siRNA caused overwhelming actin polymerization that subsequently inhibited GLUT4 translocation. This inhibition was relieved by reexpressing Xenopus wild-type cofilin-GFP but not the S3E-cofilin-GFP mutant that emulates permanent phosphorylation. Transferrin recycling was not affected by depleting Arp2/3 or cofilin. These results suggest that cofilin dephosphorylation is required for GLUT4 translocation. We propose that Arp2/3 and cofilin coordinate a dynamic cycle of actin branching and severing at the cell cortex, essential for insulin-mediated GLUT4 translocation in muscle cells.

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Ly, Thu, Natalia Moroz, Christopher T. Pappas, Stefanie M. Novak, Dmitri Tolkatchev, Dayton Wooldridge, Rachel M. Mayfield, Gregory Helms, Carol C. Gregorio, and Alla S. Kostyukova. "The N-terminal tropomyosin- and actin-binding sites are important for leiomodin 2’s function." Molecular Biology of the Cell 27, no. 16 (August 15, 2016): 2565–75. http://dx.doi.org/10.1091/mbc.e16-03-0200.

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Leiomodin is a potent actin nucleator related to tropomodulin, a capping protein localized at the pointed end of the thin filaments. Mutations in leiomodin-3 are associated with lethal nemaline myopathy in humans, and leiomodin-2–knockout mice present with dilated cardiomyopathy. The arrangement of the N-terminal actin- and tropomyosin-binding sites in leiomodin is contradictory and functionally not well understood. Using one-dimensional nuclear magnetic resonance and the pointed-end actin polymerization assay, we find that leiomodin-2, a major cardiac isoform, has an N-terminal actin-binding site located within residues 43–90. Moreover, for the first time, we obtain evidence that there are additional interactions with actin within residues 124–201. Here we establish that leiomodin interacts with only one tropomyosin molecule, and this is the only site of interaction between leiomodin and tropomyosin. Introduction of mutations in both actin- and tropomyosin-binding sites of leiomodin affected its localization at the pointed ends of the thin filaments in cardiomyocytes. On the basis of our new findings, we propose a model in which leiomodin regulates actin polymerization dynamics in myocytes by acting as a leaky cap at thin filament pointed ends.

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30

Lechler, Terry, and Rong Li. "In Vitro Reconstitution of Cortical Actin Assembly Sites in Budding Yeast." Journal of Cell Biology 138, no. 1 (July 14, 1997): 95–103. http://dx.doi.org/10.1083/jcb.138.1.95.

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We have developed a biochemical approach for identifying the components of cortical actin assembly sites in polarized yeast cells, based on a permeabilized cell assay that we established for actin assembly in vitro. Previous analysis indicated that an activity associated with the cell cortex promotes actin polymerization in the bud. After inactivation by a chemical treatment, this activity can be reconstituted back to the permeabilized cells from a cytoplasmic extract. Fractionation of the extract revealed that the reconstitution depends on two sequentially acting protein factors. Bee1, a cortical actin cytoskeletal protein with sequence homology to Wiskott-Aldrich syndrome protein, is required for the first step of the reconstitution. This finding, together with the severe defects in actin organization associated with the bee1 null mutation, indicates that Bee1 protein plays a direct role in controlling actin polymerization at the cell cortex. The factor that acts in the second step of the reconstitution has been identified by conventional chromatography. It is composed of a novel protein, Pca1. Sequence analysis suggests that Pca1 has the potential to interact with SH3 domain-containing proteins and phospholipids.

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Nishimura, Kazunari, Fumie Yoshihara, Takuro Tojima, Noriko Ooashi, Woohyun Yoon, Katsuhiko Mikoshiba, Vann Bennett, and Hiroyuki Kamiguchi. "L1-dependent neuritogenesis involves ankyrinB that mediates L1-CAM coupling with retrograde actin flow." Journal of Cell Biology 163, no. 5 (December 1, 2003): 1077–88. http://dx.doi.org/10.1083/jcb.200303060.

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The cell adhesion molecule L1 (L1-CAM) plays critical roles in neurite growth. Its cytoplasmic domain (L1CD) binds to ankyrins that associate with the spectrin–actin network. This paper demonstrates that L1-CAM interactions with ankyrinB (but not with ankyrinG) are involved in the initial formation of neurites. In the membranous protrusions surrounding the soma before neuritogenesis, filamentous actin (F-actin) and ankyrinB continuously move toward the soma (retrograde flow). Bead-tracking experiments show that ankyrinB mediates L1-CAM coupling with retrograde F-actin flow in these perisomatic structures. Ligation of the L1-CAM ectodomain by an immobile substrate induces L1CD–ankyrinB binding and the formation of stationary ankyrinB clusters. Neurite initiation preferentially occurs at the site of these clusters. In contrast, ankyrinB is involved neither in L1-CAM coupling with F-actin flow in growth cones nor in L1-based neurite elongation. Our results indicate that ankyrinB promotes neurite initiation by acting as a component of the clutch module that transmits traction force generated by F-actin flow to the extracellular substrate via L1-CAM.

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Fabrice, Tohnyui Ndinyanka, Thomas Fiedler, Vera Studer, Adrien Vinet, Francesco Brogna, Alexander Schmidt, and Jean Pieters. "Interactome and F-Actin Interaction Analysis of Dictyostelium discoideum Coronin A." International Journal of Molecular Sciences 21, no. 4 (February 21, 2020): 1469. http://dx.doi.org/10.3390/ijms21041469.

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Coronin proteins are evolutionary conserved WD repeat containing proteins that have been proposed to carry out different functions. In Dictyostelium, the short coronin isoform, coronin A, has been implicated in cytoskeletal reorganization, chemotaxis, phagocytosis and the initiation of multicellular development. Generally thought of as modulators of F-actin, coronin A and its mammalian homologs have also been shown to mediate cellular processes in an F-actin-independent manner. Therefore, it remains unclear whether or not coronin A carries out its functions through its capacity to interact with F-actin. Moreover, the interacting partners of coronin A are not known. Here, we analyzed the interactome of coronin A as well as its interaction with F-actin within cells and in vitro. Interactome analysis showed the association with a diverse set of interaction partners, including fimbrin, talin and myosin subunits, with only a transient interaction with the minor actin10 isoform, but not the major form of actin, actin8, which was consistent with the absence of a coronin A-actin interaction as analyzed by co-sedimentation from cells and lysates. In vitro, however, purified coronin A co-precipitated with rabbit muscle F-actin in a coiled-coil-dependent manner. Our results suggest that an in vitro interaction of coronin A and rabbit muscle actin may not reflect the cellular interaction state of coronin A with actin, and that coronin A interacts with diverse proteins in a time-dependent manner.

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Adler, E. M. "Acting with Actin (But Not Akt)." Science Signaling 4, no. 178 (June 21, 2011): ec169-ec169. http://dx.doi.org/10.1126/scisignal.4178ec169.

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Cingolani, Lorenzo A., and Yukiko Goda. "Erratum: Actin in action: the interplay between the actin cytoskeleton and synaptic efficacy." Nature Reviews Neuroscience 9, no. 6 (June 2008): 494. http://dx.doi.org/10.1038/nrn2410.

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35

Zeidman, Ruth, Ulrika Trollér, Arathi Raghunath, Sven Påhlman, and Christer Larsson. "Protein Kinase Cε Actin-binding Site Is Important for Neurite Outgrowth during Neuronal Differentiation." Molecular Biology of the Cell 13, no. 1 (January 2002): 12–24. http://dx.doi.org/10.1091/mbc.01-04-0210.

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We have previously shown that protein kinase Cε (PKCε) induces neurite outgrowth via its regulatory domain and independently of its kinase activity. This study aimed at identifying mechanisms regulating PKCε-mediated neurite induction. We show an increased association of PKCε to the cytoskeleton during neuronal differentiation. Furthermore, neurite induction by overexpression of full-length PKCε is suppressed if serum is removed from the cultures or if an actin-binding site is deleted from the protein. A peptide corresponding to the PKCε actin-binding site suppresses neurite outgrowth during neuronal differentiation and outgrowth elicited by PKCε overexpression. Neither serum removal, deletion of the actin-binding site, nor introduction of the peptide affects neurite induction by the isolated regulatory domain. Membrane targeting by myristoylation renders full-length PKCε independent of both serum and the actin-binding site, and PKCε colocalized with F-actin at the cortical cytoskeleton during neurite outgrowth. These results demonstrate that the actin-binding site is of importance for signals acting on PKCε in a pathway leading to neurite outgrowth. Localization of PKCε to the plasma membrane and/or the cortical cytoskeleton is conceivably important for its effect on neurite outgrowth.

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36

Egile, Coumaran, Thomas P. Loisel, Valérie Laurent, Rong Li, Dominique Pantaloni, Philippe J. Sansonetti, and Marie-France Carlier. "Activation of the Cdc42 Effector N-Wasp by the Shigella flexneri Icsa Protein Promotes Actin Nucleation by Arp2/3 Complex and Bacterial Actin-Based Motility." Journal of Cell Biology 146, no. 6 (September 20, 1999): 1319–32. http://dx.doi.org/10.1083/jcb.146.6.1319.

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To propel itself in infected cells, the pathogen Shigella flexneri subverts the Cdc42-controlled machinery responsible for actin assembly during filopodia formation. Using a combination of bacterial motility assays in platelet extracts with Escherichia coli expressing the Shigella IcsA protein and in vitro analysis of reconstituted systems from purified proteins, we show here that the bacterial protein IcsA binds N-WASP and activates it in a Cdc42-like fashion. Dramatic stimulation of actin assembly is linked to the formation of a ternary IcsA–N-WASP–Arp2/3 complex, which nucleates actin polymerization. The Arp2/3 complex is essential in initiation of actin assembly and Shigella movement, as previously observed for Listeria monocytogenes. Activation of N-WASP by IcsA unmasks two domains acting together in insertional actin polymerization. The isolated COOH-terminal domain of N-WASP containing a verprolin-homology region, a cofilin-homology sequence, and an acidic terminal segment (VCA) interacts with G-actin in a unique profilin-like functional fashion. Hence, when N-WASP is activated, its COOH-terminal domain feeds barbed end growth of filaments and lowers the critical concentration at the bacterial surface. On the other hand, the NH2-terminal domain of N-WASP interacts with F-actin, mediating the attachment of the actin tail to the bacterium surface. VASP is not involved in Shigella movement, and the function of profilin does not require its binding to proline-rich regions.

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Pollard, Thomas D. "Actin and Actin-Binding Proteins." Cold Spring Harbor Perspectives in Biology 8, no. 8 (March 17, 2016): a018226. http://dx.doi.org/10.1101/cshperspect.a018226.

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Sameshima, Masazumi, Yoshiro Kishi, Masako Osumi, Dana Mahadeo, and David A. Cotter. "Novel Actin Cytoskeleton. Actin Tubules." Cell Structure and Function 25, no. 5 (2000): 291–95. http://dx.doi.org/10.1247/csf.25.291.

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39

Fagraeus, Astrid. "Actin and anti-actin antibodies." Clinical Immunology Newsletter 6, no. 6 (June 1985): 93–94. http://dx.doi.org/10.1016/s0197-1859(85)80028-5.

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Bugalhão, Joana N., Luís Jaime Mota, and Irina S. Franco. "Bacterial nucleators: actin' on actin." Pathogens and Disease 73, no. 9 (September 27, 2015): ftv078. http://dx.doi.org/10.1093/femspd/ftv078.

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41

Ampe, Christophe, and Joël Vandekerckhove. "Actin-actin binding protein interfaces." Seminars in Cell Biology 5, no. 3 (June 1994): 175–82. http://dx.doi.org/10.1006/scel.1994.1022.

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42

Quitschke, W. W., L. DePonti-Zilli, Z. Y. Lin, and B. M. Paterson. "Identification of two nuclear factor-binding domains on the chicken cardiac actin promoter: implications for regulation of the gene." Molecular and Cellular Biology 9, no. 8 (August 1989): 3218–30. http://dx.doi.org/10.1128/mcb.9.8.3218-3230.1989.

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The cis-acting regions that appear to be involved in negative regulation of the chicken alpha-cardiac actin promoter both in vivo and in vitro have been identified. A nuclear factor(s) binding to the proximal region mapped over the TATA element between nucleotides -50 and -25. In the distal region, binding spanned nucleotides -136 to -112, a region that included a second CArG box (CArG2) 5' to the more familiar CCAAT-box (CArG1) consensus sequence. Nuclear factors binding to these different domains were found in both muscle and nonmuscle preparations but were detectable at considerably lower levels in tissues expressing the alpha-cardiac actin gene. In contrast, concentrations of the beta-actin CCAAT-box binding activity were similar in all extracts tested. The role of these factor-binding domains on the activity of the cardiac actin promoter in vivo and in vitro and the prevalence of the binding factors in nonmuscle extracts are consistent with the idea that these binding domains and their associated factors are involved in the tissue-restricted expression of cardiac actin through both positive and negative regulatory mechanisms. In the absence of negative regulatory factors, these same binding domains act synergistically, via other factors, to activate the cardiac actin promoter during myogenesis.

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43

Quitschke, W. W., L. DePonti-Zilli, Z. Y. Lin, and B. M. Paterson. "Identification of two nuclear factor-binding domains on the chicken cardiac actin promoter: implications for regulation of the gene." Molecular and Cellular Biology 9, no. 8 (August 1989): 3218–30. http://dx.doi.org/10.1128/mcb.9.8.3218.

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The cis-acting regions that appear to be involved in negative regulation of the chicken alpha-cardiac actin promoter both in vivo and in vitro have been identified. A nuclear factor(s) binding to the proximal region mapped over the TATA element between nucleotides -50 and -25. In the distal region, binding spanned nucleotides -136 to -112, a region that included a second CArG box (CArG2) 5' to the more familiar CCAAT-box (CArG1) consensus sequence. Nuclear factors binding to these different domains were found in both muscle and nonmuscle preparations but were detectable at considerably lower levels in tissues expressing the alpha-cardiac actin gene. In contrast, concentrations of the beta-actin CCAAT-box binding activity were similar in all extracts tested. The role of these factor-binding domains on the activity of the cardiac actin promoter in vivo and in vitro and the prevalence of the binding factors in nonmuscle extracts are consistent with the idea that these binding domains and their associated factors are involved in the tissue-restricted expression of cardiac actin through both positive and negative regulatory mechanisms. In the absence of negative regulatory factors, these same binding domains act synergistically, via other factors, to activate the cardiac actin promoter during myogenesis.

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44

Siton-Mendelson, Orit, and Anne Bernheim-Groswasser. "Functional Actin Networks under Construction: The Cooperative Action of Actin Nucleation and Elongation Factors." Trends in Biochemical Sciences 42, no. 6 (June 2017): 414–30. http://dx.doi.org/10.1016/j.tibs.2017.03.002.

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45

French, B. A., K. L. Chow, E. N. Olson, and R. J. Schwartz. "Heterodimers of myogenic helix-loop-helix regulatory factors and E12 bind a complex element governing myogenic induction of the avian cardiac alpha-actin promoter." Molecular and Cellular Biology 11, no. 5 (May 1991): 2439–50. http://dx.doi.org/10.1128/mcb.11.5.2439-2450.1991.

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Recent studies have shown that two genes regulating myogenesis (MyoD and myogenin) are coexpressed with cardiac alpha-actin during early stages of skeletal muscle development. Myogenin and MyoD are members of a family of regulatory proteins which share a helix-loop-helix (HLH) motif required for dimerization and DNA binding. Myogenin and MyoD form heterodimers with the ubiquitous HLH protein E12 which bind cis-acting DNA elements that have an E box (CANNTG) at their core. E boxes are present in the control regions of numerous muscle-specific genes, although their functional importance in regulating many of these genes has not yet been evaluated. In this report we examine the possibility that myogenin (or MyoD) directly transactivates the cardiac alpha-actin promoter. Heterodimers of myogenin and E12 (or MyoD and E12) specifically bound a restriction fragment extending from -200 to -103 relative to the start of cardiac alpha-actin transcription. Methylation interference footprints pinpointed the site of interaction to an E box immediately adjacent to a previously identified CArG box (CArG3). Site-directed mutations to the DNA-binding site revealed that either an intact E box or an intact CArG3 is required for induction of the cardiac alpha-actin promoter in myoblasts and for transactivation by myogenin in cotransfected fibroblasts. However, deletion and substitution experiments indicate that the complex E box/CArG3 element alone does not confer muscle-specific expression to a minimal promoter. These results suggest that direct and indirect pathways involving multiple cis-acting elements mediate the induction of the cardiac alpha-actin promoter by myogenin and MyoD.

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46

French, B. A., K. L. Chow, E. N. Olson, and R. J. Schwartz. "Heterodimers of myogenic helix-loop-helix regulatory factors and E12 bind a complex element governing myogenic induction of the avian cardiac alpha-actin promoter." Molecular and Cellular Biology 11, no. 5 (May 1991): 2439–50. http://dx.doi.org/10.1128/mcb.11.5.2439.

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Recent studies have shown that two genes regulating myogenesis (MyoD and myogenin) are coexpressed with cardiac alpha-actin during early stages of skeletal muscle development. Myogenin and MyoD are members of a family of regulatory proteins which share a helix-loop-helix (HLH) motif required for dimerization and DNA binding. Myogenin and MyoD form heterodimers with the ubiquitous HLH protein E12 which bind cis-acting DNA elements that have an E box (CANNTG) at their core. E boxes are present in the control regions of numerous muscle-specific genes, although their functional importance in regulating many of these genes has not yet been evaluated. In this report we examine the possibility that myogenin (or MyoD) directly transactivates the cardiac alpha-actin promoter. Heterodimers of myogenin and E12 (or MyoD and E12) specifically bound a restriction fragment extending from -200 to -103 relative to the start of cardiac alpha-actin transcription. Methylation interference footprints pinpointed the site of interaction to an E box immediately adjacent to a previously identified CArG box (CArG3). Site-directed mutations to the DNA-binding site revealed that either an intact E box or an intact CArG3 is required for induction of the cardiac alpha-actin promoter in myoblasts and for transactivation by myogenin in cotransfected fibroblasts. However, deletion and substitution experiments indicate that the complex E box/CArG3 element alone does not confer muscle-specific expression to a minimal promoter. These results suggest that direct and indirect pathways involving multiple cis-acting elements mediate the induction of the cardiac alpha-actin promoter by myogenin and MyoD.

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Papakonstanti, Evangelia A., and Christos Stournaras. "Association of PI-3 Kinase with PAK1 Leads to Actin Phosphorylation and Cytoskeletal Reorganization." Molecular Biology of the Cell 13, no. 8 (August 2002): 2946–62. http://dx.doi.org/10.1091/mbc.02-01-0599.

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The family of p21-activated kinases (PAKs) have been implicated in the rearrangement of actin cytoskeleton by acting downstream of the small GTPases Rac and Cdc42. Here we report that even though Cdc42/Rac1 or Akt are not activated, phosphatidylinositol-3 (PI-3) kinase activation induces PAK1 kinase activity. Indeed, we demonstrate that PI-3 kinase associates with the N-terminal regulatory domain of PAK1 (amino acids 67–150) leading to PAK1 activation. The association of the PI-3 kinase with the Cdc42/Rac1 binding-deficient PAK1(H83,86L) confirms that the small GTPases are not involved in the PI-3 kinase-PAK1 interaction. Furthermore, PAK1 was activated in cells expressing the dominant-negative forms of Cdc42 or Rac1. Additionally, we show that PAK1 phosphorylates actin, resulting in the dissolution of stress fibers and redistribution of microfilaments. The phosphorylation of actin was inhibited by the kinase-dead PAK1(K299R) or the PAK1 autoinhibitory domain (PAK1(83–149)), indicating that PAK1 was responsible for actin phosphorylation. We conclude that the association of PI-3 kinase with PAK1 regulates PAK1 kinase activity through a Cdc42/Rac1-independent mechanism leading to actin phosphorylation and cytoskeletal reorganization.

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48

Chen, Hsin, Chun-Chen Kuo, Hui Kang, Audrey S. Howell, Trevin R. Zyla, Michelle Jin, and Daniel J. Lew. "Cdc42p regulation of the yeast formin Bni1p mediated by the effector Gic2p." Molecular Biology of the Cell 23, no. 19 (October 2012): 3814–26. http://dx.doi.org/10.1091/mbc.e12-05-0400.

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Actin filaments are dynamically reorganized to accommodate ever-changing cellular needs for intracellular transport, morphogenesis, and migration. Formins, a major family of actin nucleators, are believed to function as direct effectors of Rho GTPases, such as the polarity regulator Cdc42p. However, the presence of extensive redundancy has made it difficult to assess the in vivo significance of the low-affinity Rho GTPase–formin interaction and specifically whether Cdc42p polarizes the actin cytoskeleton via direct formin binding. Here we exploit a synthetically rewired budding yeast strain to eliminate the redundancy, making regulation of the formin Bni1p by Cdc42p essential for viability. Surprisingly, we find that direct Cdc42p–Bni1p interaction is dispensable for Bni1p regulation. Alternative paths linking Cdc42p and Bni1p via “polarisome” components Spa2p and Bud6p are also collectively dispensable. We identify a novel regulatory input to Bni1p acting through the Cdc42p effector, Gic2p. This pathway is sufficient to localize Bni1p to the sites of Cdc42p action and promotes a polarized actin organization in both rewired and wild-type contexts. We suggest that an indirect mechanism linking Rho GTPases and formins via Rho effectors may provide finer spatiotemporal control for the formin-nucleated actin cytoskeleton.

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49

Bergsma, D. J., J. M. Grichnik, L. M. Gossett, and R. J. Schwartz. "Delimitation and characterization of cis-acting DNA sequences required for the regulated expression and transcriptional control of the chicken skeletal alpha-actin gene." Molecular and Cellular Biology 6, no. 7 (July 1986): 2462–75. http://dx.doi.org/10.1128/mcb.6.7.2462-2475.1986.

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We have previously observed that DNA sequences within the 5'-flanking region of the chicken skeletal alpha-actin gene harbor a cis-acting regulatory element that influences cell type and developmental stage-specific expression (J. M. Grichnik, D. J. Bergsma, and R. J. Schwartz, Nucleic Acids Res 14:1683-1701, 1986). In this report we have constructed unidirectional 5'-deletion and region-specific deletion-insertion mutations of the chicken skeletal alpha-actin upstream region and inserted these into the chloramphenicol acetyltransferase expression vector pSV0CAT. These constructions were used to locate DNA sequences that are required for developmental modulation of expression when transfected into differentiating myoblasts. With this assay we have delimited the 5' boundary of a cis-acting regulatory element to ca. 200 base pairs upstream of the mRNA cap site. In addition, we have preliminarily identified DNA sequences that may be important subcomponents within this element. A second major focus of this study was to identify those DNA signals within the regulatory element that control transcription. Toward this end, the expression phenotypes of progressive 5'-deletion and deletion-insertion mutants of the 5'-flanking region of the chicken skeletal alpha-actin gene were assayed in microinjected Xenopus laevis oocytes. These experiments defined a cis-acting transcriptional control region having a 5' border 107 base pairs preceding the alpha-actin RNA cap site. Proximal and distal functionally important regions of DNA were identified within this element. These DNA signals included within their DNA sequences the "CCAAT" and "TATA" box homologies.

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50

Bergsma, D. J., J. M. Grichnik, L. M. Gossett, and R. J. Schwartz. "Delimitation and characterization of cis-acting DNA sequences required for the regulated expression and transcriptional control of the chicken skeletal alpha-actin gene." Molecular and Cellular Biology 6, no. 7 (July 1986): 2462–75. http://dx.doi.org/10.1128/mcb.6.7.2462.

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We have previously observed that DNA sequences within the 5'-flanking region of the chicken skeletal alpha-actin gene harbor a cis-acting regulatory element that influences cell type and developmental stage-specific expression (J. M. Grichnik, D. J. Bergsma, and R. J. Schwartz, Nucleic Acids Res 14:1683-1701, 1986). In this report we have constructed unidirectional 5'-deletion and region-specific deletion-insertion mutations of the chicken skeletal alpha-actin upstream region and inserted these into the chloramphenicol acetyltransferase expression vector pSV0CAT. These constructions were used to locate DNA sequences that are required for developmental modulation of expression when transfected into differentiating myoblasts. With this assay we have delimited the 5' boundary of a cis-acting regulatory element to ca. 200 base pairs upstream of the mRNA cap site. In addition, we have preliminarily identified DNA sequences that may be important subcomponents within this element. A second major focus of this study was to identify those DNA signals within the regulatory element that control transcription. Toward this end, the expression phenotypes of progressive 5'-deletion and deletion-insertion mutants of the 5'-flanking region of the chicken skeletal alpha-actin gene were assayed in microinjected Xenopus laevis oocytes. These experiments defined a cis-acting transcriptional control region having a 5' border 107 base pairs preceding the alpha-actin RNA cap site. Proximal and distal functionally important regions of DNA were identified within this element. These DNA signals included within their DNA sequences the "CCAAT" and "TATA" box homologies.

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Journal articles on the topic 'Actin'

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