Negative Regulation of Filamentous Growth in Candida albicans by Dig1p
Ontology highlight
ABSTRACT:
ORGANISM(S): Candida albicans
PROVIDER: GSE70085 | GEO | 2015/08/31
SECONDARY ACCESSION(S): PRJNA287610
REPOSITORIES: GEO
Similar Datasets
Project description:Candida albicans is an opportunistic fungal pathogen capable of causing superficial and systemic infections in humans. The ability of C. albicans to switch between various morphological forms depending on its host environment is thought to contribute to its virulence. Filamentous growth states are associated with tissue invasion, biofilm formation, evasion of innate host defences and mating. Although the mechanisms of activation of filamentous growth pathways are well understood, less is known about which factors control the negative regulation of filamentation. In this study, we have identified a previously uncharacterized Orf that shares sequence similarity with Saccharomyces cerevisiae Dig1p and Dig2p. Deletion of the gene encoding this Orf triggers invasive growth in C. albicans and so we have retained the yeast designation of Dig1 (for Down-regulation of Invasive Growth). Mutants lacking CaDIG1 form cultures of hyperpolarized cells, form robust biofilms, are highly invasive in vitro but not in vivo and are constitutively activated for the pheromone response. Deletion of key transcription factors that act downstream of Dig1p provide evidence to suggest that CaDig1 regulates filamentation and mating through multiple signalling pathways. Transcriptional analysis of the C. albicans dig1Δ/dig1Δ homozygous mutant versus the wild type (SN148) in the MTLa/alpha background. Four biological replicates of the mutant and the wild type were included in the analysis. Samples were grown at 30 °C in YPD medium plus uridine
2015-08-31 | E-GEOD-70085 | biostudies-arrayexpress
Project description:The yeast-filament transition is essential for the virulence of a variety of fungi that are pathogenic to humans. N-acetylglucosamine (GlcNAc), a ubiquitous molecule in both the environment and host, is one of the most potent inducers of filamentation in Candida albicans and thermally dimorphic fungi such as Histoplasma capsulatum and Blastomyces dermatitidis. However, GlcNAc suppresses rather than promotes filamentation in Candida tropicalis, a fungal species that is closely related to C. albicans. Furthermore, we discover that glucose induces filamentous growth in C. tropicalis. Mutation and overexpression assays demonstrate that the conserved cAMP signaling pathway plays a central role in the regulation of filamentation in C. tropicalis. Activation of this pathway promotes filamentation in C. tropicalis, while inactivation of this pathway results in a serious growth defect in filamentation. By screening an overexpression library of 154 transcription factors, we have identified approximately 40 regulators of filamentous growth in C. tropicalis. Although most of the regulators (e.g., Tec1, Gat2, Nrg1, Sfl1, Sfl2, and Ash1) demonstrate a conserved role in the regulation of filamentation, similar to their homologs in C. albicans or S. cerevisiae, some of them are specific to C. tropicalis. For example, Czf1 and Efh1 repress filamentation, while Wor1, Zcf3, and Hcm1 promote filamentation in C. tropicalis. Bcr1, Aaf1, and Csr1 play a specific role in the process of GlcNAc-regulated filamentation. Our findings indicate that multiple interconnected signaling pathways are involved in the regulation of filamentation in C. tropicalis. These mechanisms have conserved and divergent features among different Candida species.
2016-07-01 | GSE73340 | GEO
Project description:The yeast-filament transition is essential for the virulence of a variety of fungi that are pathogenic to humans. N-acetylglucosamine (GlcNAc), a ubiquitous molecule in both the environment and host, is one of the most potent inducers of filamentation in Candida albicans and thermally dimorphic fungi such as Histoplasma capsulatum and Blastomyces dermatitidis. However, GlcNAc suppresses rather than promotes filamentation in Candida tropicalis, a fungal species that is closely related to C. albicans. Furthermore, we discover that glucose induces filamentous growth in C. tropicalis. Mutation and overexpression assays demonstrate that the conserved cAMP signaling pathway plays a central role in the regulation of filamentation in C. tropicalis. Activation of this pathway promotes filamentation in C. tropicalis, while inactivation of this pathway results in a serious growth defect in filamentation. By screening an overexpression library of 154 transcription factors, we have identified approximately 40 regulators of filamentous growth in C. tropicalis. Although most of the regulators (e.g., Tec1, Gat2, Nrg1, Sfl1, Sfl2, and Ash1) demonstrate a conserved role in the regulation of filamentation, similar to their homologs in C. albicans or S. cerevisiae, some of them are specific to C. tropicalis. For example, Czf1 and Efh1 repress filamentation, while Wor1, Zcf3, and Hcm1 promote filamentation in C. tropicalis. Bcr1, Aaf1, and Csr1 play a specific role in the process of GlcNAc-regulated filamentation. Our findings indicate that multiple interconnected signaling pathways are involved in the regulation of filamentation in C. tropicalis. These mechanisms have conserved and divergent features among different Candida species. Total RNA profiles of cells grown in Lee's glucose or Lee's GlcNAc medium.
2016-07-01 | E-GEOD-73340 | biostudies-arrayexpress
Project description:There are two mating types, “+” and “-” strains in S. scitamineum. Generally, dikaryote cells are formed after fussion of the germ turbs from both mating type strains and filamentation (filamentous growth) with infection potential occur afterward. By introducing bE2 gene and/or orther related genes, derived from the opposite mating type strain JG36, haploid mutants with filamentation characteristics were generated, including M6,M8,M9 and M10. Among these are 446 genes that were found in both filamentous haploid strains, including 237 genes up-regulated and 209 genes down-regulated. The up-regulated genes were mainly enriched in amino acid biosynthesis, starch and sucrose metabolism, secondary metabolite biosynthesis, and pentose phosphate pathways. Down-regulated expression genes are mainly enriched in fatty acid synthesis and metabolism, homologous recombination, peroxides, biosynthesis of unsaturated fatty acids, ubiquitin-mediated protein hydrolysis and other metabolic pathways. Several MAP kinases and protein kinases were up- or down-regulated in the filamentous haploid.
2024-09-01 | GSE238083 | GEO
Project description:Cellular processes are subject to variability, or noise, yet mechanisms that promote cell-to-cell uniformity are poorly understood. We have identified such a role for Dig1, a redundant (with Dig2) MAPK-responsive inhibitor of the S. cerevisiae mating pathway transcription factor Ste12. Cells lacking Dig1, but not Dig2, exhibited increased variability in outputs of the mating pathway. dig1∆ mutants also displayed a Ste12-dependent defect in growth in the absence of mating pheromone and a quantitative defect in the process of mating, itself. In cells expressing two reporter genes driven by the same promoter, both intrinsic/uncorrelated and extrinsic/correlated noise were found to increase. Remarkably, the extrinsic noise phenotype in cells lacking Dig1 correlates with the aggregation of target genes: we observed subnuclear foci of Ste12 specifically in dig1∆ cells and, using a newly-developed method to immunoprecipitate a single locus from crosslinked chromatin, we found that Dig1 inhibits long-range interactions between Ste12 target genes in vivo. Dig1 may shield binding surfaces on Ste12 whose unmasking leads to inappropriate gene associations and increased gene expression noise. These studies reveal how investigations of variability modulation mechanisms can yield unexpected biological insights.
2010-12-15 | GSE17583 | GEO
Project description:To investigate the function of Rfg1 in sensing acidic pH and regulating filamentation in C. albicans, we performed the global gene expression profile analysis of WT and rfg1/rfg1 mutant.We reveal that Rfg1 is an essential acidic pH sensor in C. albicans. Rfg1 regulates filamentous growth in acidic pH condition via co-regulation of Rim101-Phr1 pathway, cAMP signaling pathway,and the transcription factors Bcr1, Efg1, Flo8, and Hgc1.
2023-03-24 | GSE227654 | GEO
Project description:Cellular processes are subject to variability, or noise, yet mechanisms that promote cell-to-cell uniformity are poorly understood. We have identified such a role for Dig1, a redundant (with Dig2) MAPK-responsive inhibitor of the S. cerevisiae mating pathway transcription factor Ste12. Cells lacking Dig1, but not Dig2, exhibited increased variability in outputs of the mating pathway. dig1∆ mutants also displayed a Ste12-dependent defect in growth in the absence of mating pheromone and a quantitative defect in the process of mating, itself. In cells expressing two reporter genes driven by the same promoter, both intrinsic/uncorrelated and extrinsic/correlated noise were found to increase. Remarkably, the extrinsic noise phenotype in cells lacking Dig1 correlates with the aggregation of target genes: we observed subnuclear foci of Ste12 specifically in dig1∆ cells and, using a newly-developed method to immunoprecipitate a single locus from crosslinked chromatin, we found that Dig1 inhibits long-range interactions between Ste12 target genes in vivo. Dig1 may shield binding surfaces on Ste12 whose unmasking leads to inappropriate gene associations and increased gene expression noise. These studies reveal how investigations of variability modulation mechanisms can yield unexpected biological insights. The FUS1 locus is tagged with an array of lac operators. Wild type and dig1∆ cells containing this tagged FUS1 locus and expressing a mCherry-LacI were grown up for ChIP-chip. The FUS1 locus was selectively immunoprecipitated using an anti-DsRed antibody.
2010-12-15 | E-GEOD-17583 | biostudies-arrayexpress
Project description:The human fungal pathogen Candida albicans can switch stochastically and heritably between a “white” phase and an “opaque” phase. Opaque cells are the mating-competent form of the species whereas white cells are essentially “sterile”. Here, we report that glucose depletion, a common nutrient stress, enables C. albicans white cells to undergo efficient sexual mating. The relative expression levels of pheromone-sensing and mating-associated genes (including STE2/3, MFA1, MFalpha1, FIG1, FUS1, and CEK1/2) were increased under glucose depletion conditions, while expression of mating repressors TEC1 and DIG1 was decreased. We show that Cph1 and Tec1, factors that act downstream of the pheromone MAPK pathway, play opposite roles in regulating white cell mating as TEC1 deletion or CPH1 overexpression promoted white cell mating. Moreover, inactivation of the Cph1 repressor Dig1 increased white cell mating ~4,000 fold in glucose-depleted medium relative to that in the presence of glucose. These findings reveal that the white-to-opaque epigenetic switch may not be a prerequisite for sexual mating in C. albicans in nature. Given parallels between C. albicans white cell mating to that of other yeast species, this mechanism of mating could represent a more ancient strategy of sexual reproduction in C. albicans.
2023-03-03 | PXD040559 |
Project description:The capacity to sense and transduce temperature signals pervades all aspects of biology, and temperature exerts powerful control over the development and virulence of diverse pathogens. In the leading fungal pathogen of humans, Candida albicans, temperature has a profound impact on morphogenesis, a key virulence trait. Many cues that induce the transition from yeast to filamentous growth are contingent on a minimum temperature of 37ºC, while further elevatation to 39ºC serves as an independent inducing cue. The molecular chaperone Hsp90 is a key regulator of C. albicans temperature-dependent morphogenesis, as induction of filamentous growth requires relief from Hsp90-mediated repression of the morphogenetic program. Compromise of Hsp90 function genetically, pharmacologically, or by elevated temperature induces filamentation in a manner that depends on protein kinase A (PKA) signaling, but is independent of the terminal transcription factor, Efg1. Here, we determine that despite morphological and regulatory differences, inhibition of Hsp90 induces a transcriptional profile similar to that induced by other filamentation cues, and does so in a manner that is independent of Efg1. Further, we identify Hms1 as a transcriptional regulator required for morphogenesis induced by elevated temperature or compromise of Hsp90 function. Hms1 functions downstream of the cyclin Pcl, and the cyclin-dependent kinase Pho85, both of which are required for temperature-dependent filamentation. Upon Hsp90 inhibition, Hms1 binds to DNA elements involved in filamentous growth, including UME6 and RBT5, and regulates their expression, providing a mechanism through which Pho85, Pcl1, and Hms1 govern morphogenesis. Consistent with the importance of morphogenetic flexibility with virulence, deletion of C. albicans HMS1 attenuates virulence in a metazoan model of infection. Thus, we establish a new mechanism through which Hsp90 orchestrates C. albicans morphogenesis, and define novel regulatory circuitry governing a temperature-dependent developmental program, with broad implications for temperature sensing and virulence of microbial pathogens.
2012-03-20 | GSE34938 | GEO
Project description:The capacity to sense and transduce temperature signals pervades all aspects of biology, and temperature exerts powerful control over the development and virulence of diverse pathogens. In the leading fungal pathogen of humans, Candida albicans, temperature has a profound impact on morphogenesis, a key virulence trait. Many cues that induce the transition from yeast to filamentous growth are contingent on a minimum temperature of 37ºC, while further elevatation to 39ºC serves as an independent inducing cue. The molecular chaperone Hsp90 is a key regulator of C. albicans temperature-dependent morphogenesis, as induction of filamentous growth requires relief from Hsp90-mediated repression of the morphogenetic program. Compromise of Hsp90 function genetically, pharmacologically, or by elevated temperature induces filamentation in a manner that depends on protein kinase A (PKA) signaling, but is independent of the terminal transcription factor, Efg1. Here, we determine that despite morphological and regulatory differences, inhibition of Hsp90 induces a transcriptional profile similar to that induced by other filamentation cues, and does so in a manner that is independent of Efg1. Further, we identify Hms1 as a transcriptional regulator required for morphogenesis induced by elevated temperature or compromise of Hsp90 function. Hms1 functions downstream of the cyclin Pcl, and the cyclin-dependent kinase Pho85, both of which are required for temperature-dependent filamentation. Upon Hsp90 inhibition, Hms1 binds to DNA elements involved in filamentous growth, including UME6 and RBT5, and regulates their expression, providing a mechanism through which Pho85, Pcl1, and Hms1 govern morphogenesis. Consistent with the importance of morphogenetic flexibility with virulence, deletion of C. albicans HMS1 attenuates virulence in a metazoan model of infection. Thus, we establish a new mechanism through which Hsp90 orchestrates C. albicans morphogenesis, and define novel regulatory circuitry governing a temperature-dependent developmental program, with broad implications for temperature sensing and virulence of microbial pathogens.
2012-03-20 | GSE34255 | GEO