Literatura académica sobre el tema "HYPHAL MORPHOGENESIS"
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Artículos de revistas sobre el tema "HYPHAL MORPHOGENESIS"
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Hazan, Idit, Marisa Sepulveda-Becerra y Haoping Liu. "Hyphal Elongation Is Regulated Independently of Cell Cycle inCandida albicans". Molecular Biology of the Cell 13, n.º 1 (enero de 2002): 134–45. http://dx.doi.org/10.1091/mbc.01-03-0116.
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The mechanism for apical growth during hyphal morphogenesis inCandida albicans is unknown. Studies fromSaccharomyces cerevisiae indicate that cell morphogenesis may involve cell cycle regulation by cyclin-dependent kinase. To examine whether this is the mechanism for hyphal morphogenesis, the temporal appearance of different spindle pole body and spindle structures, the cell cycle-regulated rearrangements of the actin cytoskeleton, and the phosphorylation state of the conserved Tyr19 of Cdc28 during the cell cycle were compared and found to be similar between yeast and serum-induced hyphal apical cells. These data suggest that hyphal elongation is not mediated by altering cell cycle progression or through phosphorylation of Tyr19 of Cdc28. We have also shown that germ tubes can evaginate before spindle pole body duplication, chitin ring formation, and DNA replication. Similarly, tip-associated actin polarization in each hypha occurs before the events of the G1/S transition and persists throughout the cell cycle, whereas cell cycle-regulated actin assemblies come and go. We have also shown that cells in phases other than G1can be induced to form hyphae. Hyphae induced from G1cells have no constrictions, and the first chitin ring is positioned in the germ tube at various distances from the base. Hyphae induced from budded cells have a constriction and a chitin ring at the bud neck, beyond which the hyphae continue to elongate with no further constrictions. Our data suggest that hyphal elongation and cell cycle morphogenesis programs are uncoupled, and each contributes to different aspects of cell morphogenesis.
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Kornitzer, Daniel. "Regulation of Candida albicans Hyphal Morphogenesis by Endogenous Signals". Journal of Fungi 5, n.º 1 (28 de febrero de 2019): 21. http://dx.doi.org/10.3390/jof5010021.
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Candida albicans is a human commensal fungus that is able to assume several morphologies, including yeast, hyphal, and pseudohyphal. Under a range of conditions, C. albicans performs a regulated switch to the filamentous morphology, characterized by the emergence of a germ tube from the yeast cell, followed by a mold-like growth of branching hyphae. This transition from yeast to hyphal growth has attracted particular attention, as it has been linked to the virulence of C. albicans as an opportunistic human pathogen. Signal transduction pathways that mediate the induction of the hyphal transcription program upon the imposition of external stimuli have been extensively investigated. However, the hyphal morphogenesis transcription program can also be induced by internal cellular signals, such as inhibition of cell cycle progression, and conversely, the inhibition of hyphal extension can repress hyphal-specific gene expression, suggesting that endogenous cellular signals are able to modulate hyphal gene expression as well. Here we review recent developments in the regulation of the hyphal morphogenesis of C. albicans, with emphasis on endogenous morphogenetic signals.
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Lee, Hye-Jeong, Jong-Myeong Kim, Woo Kyu Kang, Heebum Yang y Jeong-Yoon Kim. "The NDR Kinase Cbk1 Downregulates the Transcriptional Repressor Nrg1 through the mRNA-Binding Protein Ssd1 in Candida albicans". Eukaryotic Cell 14, n.º 7 (22 de mayo de 2015): 671–83. http://dx.doi.org/10.1128/ec.00016-15.
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ABSTRACT NDR (nuclear Dbf2-related) kinases are essential components for polarized morphogenesis, cytokinesis, cell proliferation, and apoptosis. The NDR kinase Cbk1 is required for the hyphal growth of Candida albicans ; however, the molecular functions of Cbk1 in hyphal morphogenesis are largely unknown. Here, we report that Cbk1 downregulates the transcriptional repressor Nrg1 through the mRNA-binding protein Ssd1, which has nine Cbk1 phosphorylation consensus motifs. We found that deletion of SSD1 partially suppressed the defective hyphal growth of the C. albicans cbk1 Δ/Δ mutant and that Ssd1 physically interacts with Cbk1. Cbk1 was required for Ssd1 localization to polarized growth sites. The phosphomimetic SSD1 allele ( ssd1-9E ) allowed the cbk1 Δ/Δ mutant to form short hyphae, and the phosphodeficient SSD1 allele ( ssd1-9A ) resulted in shorter hyphae than did the wild-type SSD1 allele, indicating that Ssd1 phosphorylation by Cbk1 is important for hyphal morphogenesis. Furthermore, we show that the transcriptional repressor Nrg1 does not disappear during hyphal initiation in the cbk1 Δ/Δ mutant but is completely absent in the cbk1 Δ/Δ ssd1 Δ/Δ double mutant. Deletion of SSD1 also increased Als3 expression and internalization of the cbk1 Δ/Δ mutant in the human embryonic kidney cell line HEK293T. Collectively, our results suggest that one of the functions of Cbk1 in the hyphal morphogenesis of C. albicans is to downregulate Nrg1 through Ssd1.
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Bartnicki-Garcia, S., D. D. Bartnicki y G. Gierz. "Determinants of fungal cell wall morphology: the vesicle supply center". Canadian Journal of Botany 73, S1 (31 de diciembre de 1995): 372–78. http://dx.doi.org/10.1139/b95-271.
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Because fungal cell walls are shaped during construction, factors that regulate wall biogenesis must play a decisive role in morphogenesis. By delivering ingredients for wall formation in vesicles, fungi have a de facto mechanism to mold their own shape. The gradients in wall formation required for cell morphogenesis ensue from the pattern of vesicle discharge. A vesicle-based, mathematical model of fungal morphogenesis revealed that a relatively simple process could establish these gradients. The model and its underlying hyphoid equation assumes that wall-building vesicles emanate from a vesicle supply center (VSC). The VSC serves as an organizing center from which vesicles would move radially to the cell surface in all directions at random. VSC displacement is then an immediate cause of morphogenesis: a sustained linear displacement of the VSC would generate a polarized pattern of exocytosis required to make a hypha. The model predicts that the Spitzenkörper functions as a VSC. We have tested this prediction by analyzing instances where dislocations in Spitzenkörper position result in hyphal deformations. When the VSC was programmed to duplicate the movements of the Spitzenkörper before, during, and after a deformation, the resulting shapes mimicked closely the observed deformations. These correlations support the contention that the position and movement of the VSC determines the morphology of the fungal cell wall. The computer model has been refined to incorporate transverse random oscillations of the VSC to simulate more realistically the meandering shape of fungal hyphae. The model predicts that hyphal ring formation results from a sustained directional bias to the transverse oscillations of the Spitzenkörper. Key words: hyphal morphogenesis, Spitzenkörper, vesicle supply center, mathematical model, hyphoid equation, hyphal curvature.
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Naseem, Shamoon, Esteban Araya y James B. Konopka. "Hyphal growth inCandida albicansdoes not require induction of hyphal-specific gene expression". Molecular Biology of the Cell 26, n.º 6 (15 de marzo de 2015): 1174–87. http://dx.doi.org/10.1091/mbc.e14-08-1312.
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Various stimuli, including N-acetylglucosamine (GlcNAc), induce the fungal pathogen Candida albicans to switch from budding to hyphal growth. Previous studies suggested that hyphal morphogenesis is stimulated by transcriptional induction of a set of genes that includes known virulence factors. To better understand hyphal development, we examined the role of GlcNAc metabolism using a triple mutant lacking the genes required to metabolize exogenous GlcNAc ( hxk1Δ nag1Δ dac1Δ). Surprisingly, at low ambient pH (∼pH 4), GlcNAc stimulated this mutant to form hyphae without obvious induction of hyphal genes. This indicates that GlcNAc can stimulate a separate signal to induce hyphae that is independent of transcriptional responses. Of interest, GlcNAc could induce the triple mutant to express hyphal genes when the medium was buffered to a higher pH (>pH 5), which normally occurs after GlcNAc catabolism. Catabolism of GlcNAc raises the ambient pH rather than acidifying it, as occurs after dextrose catabolism. This synergy between alkalinization and GlcNAc to induce hyphal genes involves the Rim101 pH-sensing pathway; GlcNAc induced rim101Δ and dfg16Δ mutants to form hyphae, but hyphal gene expression was partially defective. These results demonstrate that hyphal morphogenesis and gene expression can be regulated independently, which likely contributes to pathogenesis at different host sites.
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Moreno-Ruiz, Dubraska, Linda Salzmann, Mark Fricker, Susanne Zeilinger y Alexander Lichius. "Stress-Activated Protein Kinase Signalling Regulates Mycoparasitic Hyphal-Hyphal Interactions in Trichoderma atroviride". Journal of Fungi 7, n.º 5 (6 de mayo de 2021): 365. http://dx.doi.org/10.3390/jof7050365.
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Trichoderma atroviride is a mycoparasitic fungus used as biological control agent against fungal plant pathogens. The recognition and appropriate morphogenetic responses to prey-derived signals are essential for successful mycoparasitism. We established microcolony confrontation assays using T. atroviride strains expressing cell division cycle 42 (Cdc42) and Ras-related C3 botulinum toxin substrate 1 (Rac1) interactive binding (CRIB) reporters to analyse morphogenetic changes and the dynamic displacement of localized GTPase activity during polarized tip growth. Microscopic analyses showed that Trichoderma experiences significant polarity stress when approaching its fungal preys. The perception of prey-derived signals is integrated via the guanosine triphosphatase (GTPase) and mitogen-activated protein kinase (MAPK) signalling network, and deletion of the MAP kinases Trichoderma MAPK 1 (Tmk1) and Tmk3 affected T. atroviride tip polarization, chemotropic growth, and contact-induced morphogenesis so severely that the establishment of mycoparasitism was highly inefficient to impossible. The responses varied depending on the prey species and the interaction stage, reflecting the high selectivity of the signalling process. Our data suggest that Tmk3 affects the polarity-stress adaptation process especially during the pre-contact phase, whereas Tmk1 regulates contact-induced morphogenesis at the early-contact phase. Neither Tmk1 nor Tmk3 loss-of-function could be fully compensated within the GTPase/MAPK signalling network underscoring the crucial importance of a sensitive polarized tip growth apparatus for successful mycoparasitism.
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Min, Kyunghun, Thomas F. Jannace, Haoyu Si, Krishna R. Veeramah, John D. Haley y James B. Konopka. "Integrative multi-omics profiling reveals cAMP-independent mechanisms regulating hyphal morphogenesis in Candida albicans". PLOS Pathogens 17, n.º 8 (16 de agosto de 2021): e1009861. http://dx.doi.org/10.1371/journal.ppat.1009861.
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Microbial pathogens grow in a wide range of different morphologies that provide distinct advantages for virulence. In the fungal pathogen Candida albicans, adenylyl cyclase (Cyr1) is thought to be a master regulator of the switch to invasive hyphal morphogenesis and biofilm formation. However, faster growing cyr1Δ/Δ pseudorevertant (PR) mutants were identified that form hyphae in the absence of cAMP. Isolation of additional PR mutants revealed that their improved growth was due to loss of one copy of BCY1, the negative regulatory subunit of protein kinase A (PKA) from the left arm of chromosome 2. Furthermore, hyphal morphogenesis was improved in some of PR mutants by multigenic haploinsufficiency resulting from loss of large regions of the left arm of chromosome 2, including global transcriptional regulators. Interestingly, hyphal-associated genes were also induced in a manner that was independent of cAMP. This indicates that basal protein kinase A activity is an important prerequisite to induce hyphae, but activation of adenylyl cyclase is not needed. Instead, phosphoproteomic analysis indicated that the Cdc28 cyclin-dependent kinase and the casein kinase 1 family member Yck2 play key roles in promoting polarized growth. In addition, integrating transcriptomic and proteomic data reveals hyphal stimuli induce increased production of key transcription factors that contribute to polarized morphogenesis.
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Pulver, Rebecca, Timothy Heisel, Sara Gonia, Robert Robins, Jennifer Norton, Paula Haynes y Cheryl A. Gale. "Rsr1 Focuses Cdc42 Activity at Hyphal Tips and Promotes Maintenance of Hyphal Development in Candida albicans". Eukaryotic Cell 12, n.º 4 (7 de diciembre de 2012): 482–95. http://dx.doi.org/10.1128/ec.00294-12.
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ABSTRACTThe extremely elongated morphology of fungal hyphae is dependent on the cell's ability to assemble and maintain polarized growth machinery over multiple cell cycles. The different morphologies of the fungusCandida albicansmake it an excellent model organism in which to study the spatiotemporal requirements for constitutive polarized growth and the generation of different cell shapes. InC. albicans, deletion of the landmark protein Rsr1 causes defects in morphogenesis that are not predicted from study of the orthologous protein in the related yeastSaccharomyces cerevisiae, thus suggesting that Rsr1 has expanded functions during polarized growth inC. albicans. Here, we show that Rsr1 activity localizes to hyphal tips by the differential localization of the Rsr1 GTPase-activating protein (GAP), Bud2, and guanine nucleotide exchange factor (GEF), Bud5. In addition, we find that Rsr1 is needed to maintain the focused localization of hyphal polarity structures and proteins, including Bem1, a marker of the active GTP-bound form of the Rho GTPase, Cdc42. Further, our results indicate that tip-localized Cdc42 clusters are associated with the cell's ability to express a hyphal transcriptional program and that the ability to generate a focused Cdc42 cluster in early hyphae (germ tubes) is needed to maintain hyphal morphogenesis over time. We propose that inC. albicans, Rsr1 “fine-tunes” the distribution of Cdc42 activity and that self-organizing (Rsr1-independent) mechanisms of polarized growth are not sufficient to generate narrow cell shapes or to provide feedback to the transcriptional program during hyphal morphogenesis.
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Martin, Stephen W. y James B. Konopka. "Lipid Raft Polarization Contributes to Hyphal Growth in Candida albicans". Eukaryotic Cell 3, n.º 3 (junio de 2004): 675–84. http://dx.doi.org/10.1128/ec.3.3.675-684.2004.
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ABSTRACT The polarization of sterol- and sphingolipid-enriched domains (lipid rafts) has been linked to morphogenesis and cell movement in diverse cell types. In the yeast Saccharomyces cerevisiae, a dramatic polarization of sterol-rich domains to the shmoo tip was observed in pheromone-induced cells (M. Bagnat and K. Simons, Proc. Natl. Acad. Sci. USA 99:14183-14188, 2002). We therefore examined whether plasma membrane lipid polarization contributes to the ability of the fungal pathogen Candida albicans to grow in a highly polarized manner to form hyphae. Interestingly, staining with filipin revealed that membrane sterols were highly polarized to the leading edge of growth during all stages of hyphal growth. Budding and pseudohyphal cells did not display polarized staining. Filipin staining was also enriched at septation sites in hyphae, where colocalization with septin proteins was observed, suggesting a role for the septins in forming a boundary domain. Actin appeared to play a role in sterol polarization and hyphal morphogenesis in that both were disrupted by low concentrations of latrunculin A that did not prevent budding. Furthermore, blocking either sphingolipid biosynthesis with myriocin or sterol biosynthesis with ketoconazole resulted in a loss of ergosterol polarization and caused abnormal hyphal morphogenesis, suggesting that lipid rafts are involved. Since hyphal growth is required for the full virulence of C. albicans, these results suggest that membrane polarization may contribute to the pathogenesis of this organism.
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Bensen, Eric S., Scott G. Filler y Judith Berman. "A Forkhead Transcription Factor Is Important for True Hyphal as well as Yeast Morphogenesis in Candida albicans". Eukaryotic Cell 1, n.º 5 (octubre de 2002): 787–98. http://dx.doi.org/10.1128/ec.1.5.787-798.2002.
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ABSTRACT Candida albicans is an important pathogen of immunocompromised patients which grows with true hyphal, pseudohyphal, and yeast morphologies. The dynamics of cell cycle progression are markedly different in true hyphal relative to pseudohyphal and yeast cells, including nuclear movement and septin ring positioning. In Saccharomyces cerevisiae, two forkhead transcription factors (ScFKH1 and ScFKH2) regulate the expression of B-cyclin genes. In both S. cerevisiae and Schizosaccharomyces pombe, forkhead transcription factors also influence morphogenesis. To explore the molecular mechanisms that connect C. albicans morphogenesis with cell cycle progression, we analyzed CaFKH2, the single homolog of S. cerevisiae FKH1/FKH2. C. albicans cells lacking CaFkh2p formed constitutive pseudohyphae under all yeast and hyphal growth conditions tested. Under hyphal growth conditions levels of hyphae-specific mRNAs were reduced, and under yeast growth conditions levels of several genes encoding proteins likely to be important for cell wall separation were reduced. Together these results imply that Fkh2p is required for the morphogenesis of true hyphal as well as yeast cells. Efg1p and Cph1p, two transcription factors that contribute to C. albicans hyphal growth, were not required for the pseudohyphal morphology of fkh2 mutants, implying that Fkh2p acts in pathways downstream of and/or parallel to Efg1p and Cph1p. In addition, cells lacking Fkh2p were unable to damage human epithelial or endothelial cells in vitro, suggesting that Fkh2p contributes to C. albicans virulence.
Tesis sobre el tema "HYPHAL MORPHOGENESIS"
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Laissue, P. P. "Morphogenesis of a filamentous fungus : dynamics of the actin cytoskeleton and control of hyphal integrity in Ashbya gossypii". Thesis, University of Kent, 2004. https://kar.kent.ac.uk/12170/.
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Chapa, y. Lazo Bernardo. "Molecular biology of morphogenesis in Candida albicans : Cln3 has a role in the regulation of the cell cycle and hyphal growth, and Nap1 is required for septin ring fomation only in hyphae". Thesis, University of Sheffield, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.425620.
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Murad, Abdul Munir Abdul. "The role of NRG1 in the control of cellular morphogenesis in Candida albicans". Thesis, University of Aberdeen, 2001. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU602288.
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This thesis describes the isolation and characterisation of the C. albicans NRG1 gene, which encodes a repressor of filamentous growth in this pathogenic fiingus. A C. albicans SBP1 cDNA was previously isolated in a screen for transacting factors that bind to a STRE-like element (consensus sequence: CCCCT) (Leng, 1999). In S. cerevisiae, STRE is a stress-responsive element that is required for the regulation of many stress-responsive genes (Marchler et al., 1993). In C. albicans, this element had been identified in the promoters of two hypha-specific genes, ALS8 and HYR1. Since many conditions that induce yeast-hypha morphogenesis in C. albicans impose a stress, it was proposed that the STRE- binding protein (Sbpl) might influence yeast-hypha morphogenesis and/or stress responses in this human pathogen. The cDNA was then used to isolate the complete C. albicans SBP1 locus by colony hybridisation. Both the cDNA and gene were sequenced, revealing an ORF capable of encoding a protein of 310 amino acids containing a C2H2-zinc finger motifs near its C-terminus. The zinc finger region of this protein displayed the highest sequence similarity to S. cerevisiae NRG1 (67 % identity), and hence the gene was renamed CaNRGl. To examine the role of CaNrgl, a C. albicans nrgl/nrgl null mutant and a mutant over-expressing the NRG1 gene were created. Overexpression of NRG1 did not reveal any obvious phenotypes, but inactivation of NRG1 caused constitutive filamentous and invasive growth, as well as increased sensitivity to some stresses. Also, the expression of the hypha-specific genes, ALS8, ECE1, HWP1 and HYR1, was derepressed in the nrgl/nrgl mutants. Similar phenotypes were observed for a C. albicans tupl/tupl null mutant. These observations suggest that Nrgl represses filamentous growth in C. albicans, possibly by recruiting Tupl to specific promoters. Unlike the tupl/tupl mutant, nrgl/nrgl cells formed normal hyphae following pH and serum stimulation, they generated chlamydospores at normal rates, and they grew at 42 C. Transcript profiling of 2002 C. albicans genes revealed that Nrgl regulates a subset of Tupl-repressed genes, which includes known hypha- specific genes and some virulence factors. The data also showed that Tupl regulates other genes, which are not regulated by Nrgl, including glucose sensitive genes, amino acid and sterol biosynthesis genes, and genes encoding other virulence determinants. Taken together, this study demonstrates that Nrgl is a transcriptional repressor that regulates a set of functions required for yeast-hypha morphogenesis and virulence in C. albicans.
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Lacroix, Céline. "Nrg1p and Rfg1p in Candida albicans yeast-to-hyphae transition". Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112528.
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The ability of Candida albicans to change morphology plays several roles in its virulence and as a human commensal. The yeast-to-hyphae transition is tightly regulated by several sets of activating and repressing pathways. The DNA-binding proteins Rfg1p, Nrg1p and the global repressor Tup1p are part of the repressors found to regulate this morphogenesis. Knowledge of these repressors is based on extrapolations from homology to S. cerevisiae and from expression studies of mutants in inducing conditions, all of which are indirect means of determining a protein's function. We proposed a genome-wide location study of the Nrg1 and Rfg1 transcription factors to obtain direct data to identify their in vivo targets. Our results suggest different avenues for Nrg1p function and a regulation behaviour diverging from the previously suggested model: Nrg1p acts not only as a repressor but also as a transcription activator. Furthermore it regulates its target genes through binding in their coding regions instead binding to the expected regulatory elements on promoters.
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Wang, Chih-Li. "Assessing the Roles of Striatin Orthologs in Fungal Morphogenesis, Sexual Development and Pathogenicity". Thesis, 2011. http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9935.
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Striatin family proteins contain a caveolin binding domain, a coiled-coil motif, a calmodulin binding domain, and a WD-repeat domain. Homologs of striatin protein have been However, our knowledge of the function and the molecular mechanism of fungal striatin homologs is limited. Based on the conserved sequences of functional domains, I hypothesized that the fungal striatin orthologs also act as scaffolding proteins that are functionally conserved among fungal species and involved in multiple types of development in the diverse kingdom Mycota. I used reverse genetic strategies to study the function of the Aspergillus nidulans striatin ortholog (strA) and the Colletotrichum graminicola striatin ortholog (str1). In assays of sexual development, the strA deletion strain (ΔstrA) produces fewer ascospores with smaller cleistothecia, while the str1 deletion strain (Δstr1) is defective in perithecia development. The ΔstrA phenotypes indicate that StrA is associated with ascosporogenesis in cleistothecia. Both ΔstrA and Δstr1 are reduced in radial growth and in conidia production. The Δstr1 strain is also altered in its spiral growth pattern and morphology of conidia and hyphopodia, but it produces appressoria similar to wild type. The pairing of nitrate non-utilizing mutants demonstrates that Str1 is required for hyphal fusion. In pathogenicity, Δstr1 is less virulent in maize anthracnose leaf blight and stalk rot. The phenotypes of Δstr1 are complemented by the Fusarium verticillioides striatin ortholog (fsr1), indicating that Fsr1 and Str1 are functionally conserved. Over-expression of StrA reveals its positive role in conidiation and the sexual production. StrA::eGFP localizes mainly to the endoplasmic reticulum. After comparing the results from these two species and other studied fungal species, I suggest that fungal striatins are involved in five types of development including hyphal growth, hyphal fusion, conidiation, sexual development, and virulence, and propose a model of fungal striatin protein interactions to account for these diverse phenotypes.
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DWIVEDI, PRAVEEN KUMAR. "CHARACTERIZATION OF EFFECTS OF FORMULATED PLANT EXTRACTS (NUTMEG AND PEPPER) ON HYPHAL MORPHOGENESIS IN CANDIDA ALBICANS". Thesis, 2016. http://dspace.dtu.ac.in:8080/jspui/handle/repository/15536.
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Candida species are normally harmless commensal organisms of the gastrointestinal and genitourinary tract but sometimes in immunodeficiency conditions of host this fungus becomes pathogen which causes a range of disease from superficial to life threatening systemic superficial infections in human immunodeficiency virus (HIV) patients and immunocompromised individual. Life-threatening blood branched infections along compromising or threatened intensive care patients (mainly those undergoing cancer chemotherapy or immunosuppressive medication because of organ or bone marrow transplant procedures). They spread out or enlarge in many different or distinguishable morphological forms which purview or reach from unicellular budding yeast to true Hyphal with collateral or symmetric -side wall (Sudbery P et al., 2004). In a typical manner regularly, C. albicans capture about or nearly 70% of the population or group of individuals and C. albicans are mainly occurring as harmless commensal i.e. it profits other without any negative effect while some C. albicans are also found in the urinary tract and GIT in human body. (Kabir M AA et al., 2012).
It is found that Candida causes some kind of diseases like oral, pharyngeal, vaginal, and invasive or incursive Candidiasis. It is also found that approx. 70% of the females will face or experience these kinds of diseases which are influenced by C.albicans, generally vaginal Candidiasis, in their lifespan. More often, the infections occur by C.albicans is inheritable by patients in hospitals with the death rate of approx. 45% (Pfaller MA et al., 2006). Oral and pharyngeal fungal infection is a white spot or patch of C.albicans on mucous membranes and this fungal disease come about or arise in the buccal chamber or throat. Vulvovaginal fungal infection is known by the unreasonable growth of Yeast in the vulvovaginal area causing some haptic sensation, and extraction of fluid from the vaginal region. Infection comes about when the Candida move into the inpatients blood
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stream and can conveniently spread through a higher level to almost many distinct organs of end to end body. Incursive candidiasis is best acknowledged when body (of host or individual) fever becomes incurable with antibiotics. Mainly, azoles are meant for curing Yeast or fungal diseases while it is also found that fluconazole is meant for curing some intense disease (Ortega et al., 2011).
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SINGH, ANJU LATA. "CHARACTERIZATION OF EFFECTS OF SILVER NANOPARTICLES ON HYPHAL MORPHOGENESIS IN AN OPPORTUNISTIC FUNGAL PATHOGEN CANDIDA ALBICANS". Thesis, 2016. http://dspace.dtu.ac.in:8080/jspui/handle/repository/15155.
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Candida albicans, the polymorphic fungus, is a member of the normal human microbiome and a harmless commensal organism which emerged as major human pathogen and is able to cause life threatening diseases in immunocompromised persons. Several factors have been identified which contributes the pathogenic prospective to fungus including molecules mediate adhesion to invasion into host cells, phenotypic switching, transition from yeast to hyphal, contact sensing, thigmotropism and formation of biofilm. Their treatment is restricted due to appearance of multi drug resistance (MDR), emergence of drug resistance strains, high toxicity of drug and narrow range of the accessible drugs. In the effort to launch newer therapeutic strategies to setback MDR need to find novel determinants of drug resistance in Candida albicans. The antifungal drugs present nowadays are very few which is being used clinically. These are the reasons which restrict the clinician’s therapeutic choices to the fungal pathogen Candida albicans. Silver has been recognized as a nontoxic, safe inorganic antifungal agent with various properties used for centuries. Silver demonstrates a very high potential in a wide range of biological applications, more particularly in the form of nanoparticles. In this study we are synthesizing the silver nanoparticles (AgNPs) by chemical reduction method and characterizing the effects of AgNPs on hyphal morphogenesis in Candida albicans.
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Shareck, Julie. "Effect of fatty acids on hyphal growth in the pathogenic yeast Candida albicans". Thèse, 2011. http://hdl.handle.net/1866/5494.
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Candida albicans est une levure pathogène qui, à l’état commensal, colonise les muqueuses de la cavité orale et du tractus gastro-intestinal. De nature opportuniste, C. albicans cause de nombreuses infections, allant des candidoses superficielles (muguet buccal, vulvo-vaginite) aux candidoses systémiques sévères. C. albicans a la capacité de se développer sous diverses morphologies, telles que les formes levures, pseudohyphes et hyphes. Des stimuli environnementaux mimant les conditions retrouvées chez l’hôte (température de 37°C, pH neutre, présence de sérum) induisent la transition levure-à-hyphe (i.e. morphogenèse ou filamentation). Cette transition morphologique contribue à la pathogénicité de C. albicans, du fait que des souches présentant un défaut de filamentation sont avirulentes. Non seulement la morphogenèse est un facteur de virulence, mais elle constituerait aussi une cible pour le développement d’antifongiques. En effet, il a déjà été démontré que l’inhibition de la transition levure-à-hyphe atténuait la virulence de C. albicans lors d’infections systémiques. Par ailleurs, des études ont démontré que de nombreuses molécules pouvaient moduler la morphogenèse. Parmi ces molécules, certains acides gras, dont l’acide linoléique conjugué (CLA), inhibent la formation d’hyphes. Ainsi, le CLA posséderait des propriétés thérapeutiques, du fait qu’il interfère avec un déterminant de pathogénicité de C. albicans. Par contre, avant d’évaluer son potentiel thérapeutique dans un contexte clinique, il est essentiel d’étudier son mode d’action.
Ce projet vise à caractériser l’activité anti-filamentation des acides gras et du CLA et à déterminer le mécanisme par lequel ces molécules inhibent la morphogenèse chez C. albicans. Des analyses transcriptomiques globales ont été effectuées afin d’obtenir le profil transcriptionnel de la réponse de C. albicans au CLA. L’acide gras a entraîné une baisse des niveaux d’expression de gènes encodant des protéines hyphes-spécifiques et des régulateurs de morphogenèse, dont RAS1. Ce gène code pour la GTPase Ras1p, une protéine membranaire de signalisation qui joue un rôle important dans la transition levure-à-hyphe. Des analyses de PCR quantitatif ont confirmé que le CLA inhibait l’induction de RAS1. De plus, le CLA a non seulement causé une baisse des niveaux cellulaires de Ras1p, mais a aussi entraîné sa délocalisation de la membrane plasmique. En affectant les niveaux et la localisation cellulaire de Ras1p, le CLA nuit à l’activation de la voie de signalisation Ras1p-dépendante, inhibant ainsi la morphogenèse. Il est possible que le CLA altère la structure de la membrane plasmique et affecte indirectement la localisation membranaire de Ras1p. Ces travaux ont permis de mettre en évidence le mode d’action du CLA. Le potentiel thérapeutique du CLA pourrait maintenant être évalué dans un contexte d’infection, permettant ainsi de vérifier qu’une telle approche constitue véritablement une stratégie pour le traitement des candidoses.The yeast Candida albicans is an inhabitant of the oral cavity, the gastrointestinal and genitourinary tracts of humans. Generally encountered as a commensal, it is also an opportunistic pathogen that causes a spectrum of infections, ranging from superficial mycoses (thrush, vulvovaginitis) to severe and life-threatening systemic infections. A striking feature of C. albicans is its ability to grow in different morphological forms, including budding yeasts, pseudohyphae, and hyphae. Environmental cues that mimic host conditions (elevated temperature, neutral or alkaline pH, and serum) induce the yeast-to-hypha transition. Morphogenesis is considered to be an attribute of pathogenesis, as mutants locked as yeasts or filamentous forms are avirulent. Given that the yeast-to-hypha transition is a virulence factor, it may also constitute a target for the development of antifungal drugs. Indeed, evidence has shown that impairing morphogenesis is a means to treat systemic candidiasis. Concurrently, a number of molecules have been reported to modulate morphogenesis in C. albicans. For instance, several fatty acids, including conjugated linoleic acid (CLA), inhibited the yeast-to-hypha transition. By interfering with an important attribute of C. albicans pathogenesis, CLA may harbor antifungal properties. However, before assessing its therapeutic potential in a clinical context, it is mandatory to address CLA’s mode of action. The present study aims to further characterize the hypha-inhibiting properties of fatty acids and CLA and to elucidate the mechanism by which these molecules inhibit the yeast-to-hypha transition in C. albicans. Gene expression analyses were performed to gain insight into the transcriptional response of cells to CLA on a genome-wide scale and to probe the fatty acid’s mode of action. CLA downregulated the expression of hypha-specific genes and blocked the induction of genes encoding regulators of hyphal growth, including that of RAS1, which encodes the small GTPase Ras1p. A membrane-associated signaling protein, Ras1p plays a major role in morphogenesis. Quantitative PCR analyses showed that CLA prevented the increase in RAS1 mRNA levels which occurred at the onset of the yeast-to-hypha transition. Unexpectedly, CLA reduced the steady-state levels of Ras1p. Additionally, CLA caused the delocalization of GFP-Ras1p from the plasma membrane. These findings indicate that CLA treatment results in suboptimal Ras1p cellular concentrations and localization, which impedes Ras1p signaling and inhibits the yeast-to-hypha transition. CLA may indirectly affect Ras1p localization by altering the structure of the plasma membrane. These studies have provided the mechanism underlying CLA’s hypha-inhibiting properties and may serve as the rationale to examine CLA’s therapeutic potential in the context of a Candida infection. There is a general lack of clinical evidence demonstrating that impairing morphogenesis is a sound approach to treat candidiasis. To remedy this situation, the therapeutic potential of molecules that modulate morphogenesis, such as CLA, should be clinically assessed.
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Klengel, Torsten. "Molekulare Charakterisierung der Carboanhydrase Nce103 im Kontext des CO2 induzierten Polymorphismus in Candida albicans". Doctoral thesis, 2008. https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-34573.
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Die Detektion von Umweltsignalen und die gezielte zelluläre Reaktion ist eine zentrale und für das Überleben aller Lebewesen essentielle Fähigkeit. Candida albicans, als dominierender humanpathogener Pilz, ist hochgradig verschiedenen biochemischen und physikalischen Umweltbedingungen ausgesetzt, welche sowohl die Zellmorphologie als auch die Virulenz dieses Erregers beeinflussen. In der vorliegenden Arbeit wurde der Einfluss von Kohlendioxid, als ubiquitär vorkommendes Gasmolekül, auf die Zellmorphologie und Virulenz untersucht. Erhöhte Konzentrationen von Kohlendioxid stellen ein äußerst robustes Umweltsignal dar, welches die morphologische Transition vom Hefewachstum zum hyphalen Wachstum, einem Hauptvirulenzfaktor, in Candida albicans stimuliert. In diesem Zusammenhang wurde die Rolle der putativen Carboanhydrase Nce103 durch die Generation von knock – out Mutanten untersucht. Die Disruption von NCE103 in C. albicans führt zu einem Kohlendioxid – abhängigen Phänotyp, welcher Wachstum unter aeroben Bedingungen (ca. 0,033% CO2) nicht zulässt, jedoch unter Bedingungen mit einem erhöhten CO2 Gehalt von ca. 5% ermöglicht. NCE103 ist also für das Wachstum von C. albicans in Wirtsnischen mit aeroben Bedingungen essentiell. Durch Untersuchungen zur Enzymkinetik mittels Stopped – flow wurde in dieser Arbeit gezeigt, dass Nce103 die Funktion einer Carboanhydrase erfüllt. Die biochemische Funktion dieser Carboanhydrase besteht in der Fixation von CO2 bzw. HCO3ˉ in der Zelle zur Unterhaltung der wesentlichen metabolischen Reaktionen. Weiterhin konnte gezeigt werden, dass die Induktion hyphalen Wachstums durch CO2 in C. albicans nicht durch den Transport von CO2 mittels des Aquaporins Aqy1 beeinflusst wird. CO2 bzw. HCO3ˉ aktiviert in der Zelle direkt eine Adenylylcyclase (Cdc35), welche sich grundlegend von den bisher gut charakterisierten G-Protein gekoppelten Adenylylcylasen unterscheidet. Die Generation von cAMP beeinflusst in der Folge direkt die Transkription hyphenspezifischer Gene und nachfolgend die morphologische Transition vom Hefewachstum zum elongierten, hyphalen Wachstum. Dieser Mechanismus konnte sowohl in Candida albicans als auch in Cryptococcus neoformans nachgewiesen werden, was auf einen panfungal konservierten Signaltransduktionsmechanismus schliessen lässt. Die Inhibition dieser spezifischen Kaskade eröffnet neue Ansätze zur Entwicklung spezifischer antimykotischer WirkstoffeDetection of environmental signals and subsequently directed reaction is essential for the survival of all living organisms. Candida albicans, as the predominant human fungal pathogen is exposed to severely different physical and chemical conditions, which influence cell morphology as well as virulence in human. In the present work, the influence of carbon dioxide as ubiquitous gaseous molecule on virulence and cell morphology was analysed. Elevated concentrations of carbon dioxide are a robust signal to induce the morphological transition from yeast growth to an elongated hyphal growth form, which is believed to be one of the main virulence factors in Candida albicans. The role of the putative carbonic anhydrase Nce103p in carbon dioxide signalling is reviewed by generating knockout mutant strains, which exhibited a carbon dioxide dependent phenotype. Growth under aerobic conditions (0,033 % carbon dioxide) is inhibited but feasible in 5% carbon dioxide. Therefore, Nce103p is essential for growth in host niches with aerobic conditions. Analysis of the biochemical properties of Nce103p by stopped – flow kinetics revealed carbonic anhydrase activity. It is hypothesised, that Nce103p is essential for fixation of carbon dioxide and bicarbonate within the cell in order to sustain basic metabolic reactions. Furthermore, the induction of hyphal growth was independent of aquaporine-mediated transport of carbon dioxide. Bicarbonate rather carbon dioxide activates directly the adenylyl cyclase Cdc35p generating cyclic AMP as second messenger and influencing the transcription of hyphal specific genes in Candida albicans thus promoting the morphological transition from yeast growth to elongated hyphal growth. This signal transduction cascade is present in Candida albicans as well as Cryptococcus neoformans and it is believed to be a pan fungal signal transduction cascade. The specific inhibition of carbon dioxide mediated polymorphism may serve as a new target for antifungal therapeutic agents
Capítulos de libros sobre el tema "HYPHAL MORPHOGENESIS"
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Sietsma, J. H., C. A. Vermeulen y J. G. H. Wessels. "The Role of Chitin in Hyphal Morphogenesis". En Chitin in Nature and Technology, 63–69. Boston, MA: Springer US, 1986. http://dx.doi.org/10.1007/978-1-4613-2167-5_9.
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Horiuchi, Hiroyuki y Takuya Katayama. "Protein Kinase C of Filamentous Fungi and Its Roles in the Stresses Affecting Hyphal Morphogenesis and Conidiation". En Stress Biology of Yeasts and Fungi, 185–98. Tokyo: Springer Japan, 2015. http://dx.doi.org/10.1007/978-4-431-55248-2_12.
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"Metabolism and Biochemistry of Hyphal Systems". En Fungal Morphogenesis, 71–133. Cambridge University Press, 1998. http://dx.doi.org/10.1017/cbo9780511529887.004.
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"The Genetic Component of Hyphal Differentiation". En Fungal Morphogenesis, 191–245. Cambridge University Press, 1998. http://dx.doi.org/10.1017/cbo9780511529887.006.
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"Hyphal Morphogenesis in Aspergillus nidulans". En The Aspergilli, 231–42. CRC Press, 2007. http://dx.doi.org/10.1201/9781420008517-20.
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Harris, Steven. "Hyphal Morphogenesis in Aspergillus nidulans". En Mycology, 211–22. CRC Press, 2007. http://dx.doi.org/10.1201/9781420008517.ch14.
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BARTNICKI-GARCIA, SALOMON. "Role of Vesicles in Apical Growth and a New Mathematical Model of Hyphal Morphogenesis". En Tip Growth In Plant and Fungal Cells, 211–32. Elsevier, 1990. http://dx.doi.org/10.1016/b978-0-12-335845-5.50011-2.
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"Hypal Growth". En Fungal Morphogenesis, 26–70. Cambridge University Press, 1998. http://dx.doi.org/10.1017/cbo9780511529887.003.
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Fallacara, Giuseppe y Maurizio Barberio. "Parametric Morphogenesis, Robotic Fabrication, and Construction of Novel Stereotomic Hypar Morphologies". En Advances in Media, Entertainment, and the Arts, 329–53. IGI Global, 2018. http://dx.doi.org/10.4018/978-1-5225-3993-3.ch016.
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The chapter explains the studies the New Fundamentals Research Group is carrying out on the digital update of stereotomy. Between the various experiments, the chapter focuses on the group or prototypes designed by the geometry of the hyperbolic paraboloid, both at the macro (architectural organism) and micro scale (architectural elements). Several full-scale prototypes have been designed and built, using specific parametric codes, to define the geometrical morphogenesis properties of the built structural morphologies. Consequent theoretical reflections are fully explained.
Actas de conferencias sobre el tema "HYPHAL MORPHOGENESIS"
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Bracker, Charles E., Douglas J. Murphy y Rosamaria Lopez-Franco. "Laser microbeam manipulation of cell morphogenesis growing in fungal hyphae". En BiOS '97, Part of Photonics West, editado por Daniel L. Farkas y Bruce J. Tromberg. SPIE, 1997. http://dx.doi.org/10.1117/12.274325.
Texto completoInformes sobre el tema "HYPHAL MORPHOGENESIS"
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Dickman, Martin B. y Oded Yarden. Regulation of Early Events in Hyphal Elongation, Branching and Differentiation of Filamentous Fungi. United States Department of Agriculture, 2000. http://dx.doi.org/10.32747/2000.7580674.bard.
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In filamentous fungi, hyphal elongation, branching and morphogenesis are in many cases the key to successful saprophytic and pathogenic fungal proliferation. The understanding of the fungal morphogenetic response to environmental cues is in its infancy. Studies concerning the regulation of fungal growth and development (some of which have been obtained by the participating collaborators in this project) point to the fact that ser/thr protein kinases and phosphatases are (i) involved in the regulation of such processes and (ii) share common structural and functional features between saprophytes and pathogens. It is our objective to combine a pharmaceutical and a genetic approach in order to identify, characterize and functionally dissect some of the regulatory factors involved in hyphal growth, branching and differentiation. Using an immunohistochemical approach, a ser/thr protein kinase involved in hyphal elongation in both Neurospora crassa and Colletotrichum trifolii has been localized in order to identify the physical arena of regulation of hyphal elongation. The analysis of additional kinases and phosphatases (e.g. Protein kinase C, cAMP-dependent kinase, lipid-activated protein kinase, components of the type 2A protein phosphatase) as well as a RAS-related gene (an additional key participant in signal transduction) has been performed. In order to succeed in advancing the goals of this project, we have taken advantage of available elongation/branching mutants in N. crassa and continuously combined the accumulated information obtained while studying the two systems in order to dissect the elements involved in these processes. The various inhibitors/effectors analyzed can serve as a basis for modification to be used as anti-fungal compounds. Understanding the regulation of hyphal proliferation is a key requirement for identifying novel target points for either curbing fungal growth (as in the case of pathogenesis) or affecting growth patterns in various biotechnological processes. The major objective of our joint project was to advance our understanding of regulation of hyphal growth, especially during early events of fungal germination. Towards achieving this goal, we have coupled the analysis of a genetically tractable organism (N. crassa) with a plant pathogen o economic importance (C. trifolii). As the project progressed we believe that the results obtained have provided a reinforcement to our basic approach which called for combining the two fungal systems for a joint research project. On the one hand, we feel that much of the advance made was possible due to the amenability of N. crassa to genetic manipulations. The relevance of some of the initial findings obtained in Neurospora have been proven to be relevant to the plant pathogen while unique features of the pathogen have been identified in Colletotrichum. Most of the results obtained from this research project have been published. Thus, the main volume of this report is comprised of the relevant publications describing the research and results obtained.
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Dickman, Martin B. y Oded Yarden. Phosphorylative Transduction of Developmental and Pathogenicity-Related Cues in Sclerotinia Sclerotiorum. United States Department of Agriculture, abril de 2004. http://dx.doi.org/10.32747/2004.7586472.bard.
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Sclerotinia sclerotiorum (Lib.) de Bary is among the world's most successful and omnivorous fungal plant pathogens. Included in the more than 400 species of plants reported as hosts to this fungus are canola, alfalfa, soybean, sunflower, dry bean, and potato. The general inability to develop resistant germplasm with these economically important crops to this pathogen has focused attention on the need for a more detailed examination of the pathogenic determinants involved in disease development. This proposal involved experiments that examined the involvement of protein phosphorylation during morphogenesis (hyphal elongation and sclerotia formation) and pathogenesis (oxalic acid). Data obtained from our laboratories during the course of this project substantiates the fact that kinases and phosphatases are involved and important for these processes. A mechanistic understanding of the successful strategy(ies) used by S . sclerotiorum in infecting and proliferating in host plants and this linkage to fungal development will provide targets and/or novel approaches with which to design resistant crop plants including interference with fungal pathogenic development. The original objectives of this grant included: I. Clone the cyclic AMP-dependent protein kinase A (PKA) catalytic subunit gene from S.sclerotiorum and determine its role in fungal pathogenicity, OA production (OA) and/or morphogenesis (sclerotia formation). II. Clone and characterize the catalytic and regulatory subunits of the protein phosphatase PP2A holoenzyme complex and determine their role in fungal pathogenicity and/or morphogenesis as well as linkage with PKA-regulation of OA production and sclerotia formation. III. Clone and characterize the adenylate cyclase-encoding gene from S . sclerotiorum and detennine its relationship to the PKA/PP2A-regulated pathway. IV. Analyze the expression patterns of the above-mentioned genes and their products during pathogenesis and determine their linkage with infection and fungal growth.
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Dickman, Martin B. y Oded Yarden. Modulation of the Redox Climate and Phosphatase Signaling in a Necrotroph: an Axis for Inter- and Intra-cellular Communication that Regulates Development and Pathogenicity. United States Department of Agriculture, agosto de 2011. http://dx.doi.org/10.32747/2011.7697112.bard.
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The long-term goals of our research are to understand the regulation of sclerotial development and pathogenicity in S. sclerotiorum. The focus in this project is on the elucidation of the signaling events and environmental cues that contribute to broad pathogenic success of S. sclerotiorum. In this proposal, we have taken advantage of the recent conceptual (ROS/PPs signaling) and technical (genome sequence availability and gene inactivation possibilities) developments to address the following questions, as appear in our research goals stated below, specifically concerning the involvement of REDOX signaling and protein dephosphorylation in the regulation of hyphal/sclerotial development and pathogenicity of S. sclerotiorum. Our stated specific objectives were to progress our understanding of the following questions: (i) Which ROS species affect S. sclerotiorum development and pathogenicity? (ii) In what manner do PPs affect S. sclerotiorum development and pathogenicity? (iii) Are PPs affected by ROS production and does PP activity affect ROS production and SMK1? (iv) How does Sclerotinia modulate the redox environment in both host and pathogen? While addressing these questions, our main findings include the identification and characterization the NADPH oxidase (NOX) family in S. sclerotiorum. Silencing of Ssnox1 indicated a central role for this enzyme in both virulence and pathogenic (sclerotial) development, while inactivation of Ssnox2 resulted in limited sclerotial development but remained fully pathogenic. Interestingly, we found a consistent correlation with Ssnox1(involved with pathogenicity) and oxalate levels. This same observation was also noted with Sssod1. Thus, fungal enzymes involved in oxidative stress tolerance,when inactivated, also exhibit reduced OA levels. We have also shown that protein phosphatases (specifically PP2A and PTP1) are involved in morphogenesis and pathogenesis of S. sclerotiorum, demonstrating the regulatory role of these key proteins in the mentioned processes. While probing the redox environment and host-pathogen interactions we determined that oxalic acid is an elicitor of plant programmed cell death during S. sclerotiorum disease development and that oxalic acid suppresses host defense via manipulation of the host redox environment. During the course of this project we also contributed to the progress of understanding S. sclerotiorum function and the manipulation of this fungus by establishing an efficient gene replacement and direct hyphal transformation protocols in S. sclerotiorum. Lastly, both PIs were involved in thegenomic analysis of this necrotrophic fungal pathogen (along with Botrytis cinerea). Our results have been published in 11 papers (including joint papers and refereed reviews) and have set the basis for a continuum towards a better understanding and eventual control of this important pathogen (with implications to other fungal-host systems as well).