SAGA Complex Subunits in Candida albicans Differentially Regulate Filamentation, Invasiveness and Biofilm Formation
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PROVIDER: PRJNA798386 | ENA |
REPOSITORIES: ENA
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Project description:In this study we were interested in studying the role of SAGA subunits in various cellular processes- morphogenetic changes, growth, invasiveness, biofilm formation and to check the role of these subunits under various cellular and genotoxic conditions. In this work, we investigated conditional and null mutants of components of the SAGA complex modules; Ngg1 of the HAT module, Ubp8 of the Dub module, Tra1 of the recruitment module, Spt7 of the architecture module, and Spt8 of the TBP interaction unit to assess their role in processes such as filamentation, invasiveness, and biofilm formation. Spt7 and Spt8 deletion in Candida albicans resulted in ifilamentatation, invasiveness in YPD media at 30 degrees Celsius and also showed sensitivity to antifungal drugs. Wild type SN148 do not make any filaments in YPD at 30 degrees Celsius and didn't show antifungal sensitivity . The aim was to look for transcription profiling of SAGA mutants against wild type to find genes up and down regulated in the mutant especially those ones critical for filamentation, invasiveness and antifungal drug resistance.
2022-03-09 | GSE193907 | GEO
Project description:ChIP-nexus performed in Kc167 cells for subunits of the SAGA coactivator complex;ChIP performed in ovary homogenate for subunits of the SAGA coactivator complex
2021-10-29 | GSE166224 | GEO
Project description:Morphogenetic transitions are prevalent in the fungal kingdom. For a leading human fungal pathogen, Candida albicans, the capacity to transition between yeast and filaments is key for virulence. For the model yeast Saccharomyces cerevisiae, filamentation enables nutrient acquisition. A recent functional genomic screen in S. cerevisiae identified Mfg1 as a regulator of morphogenesis that acts in complex with Flo8 and Mss11 to enable transcriptional responses crucial for filamentation. In C. albicans, Mfg1 also interacts physically with Flo8 and Mss11 and is critical for filamentation in response to diverse cues, but the mechanisms through which it regulates morphogenesis remained elusive. Here, we explored the consequences of perturbation of Mfg1, Flo8, and Mss11 on C. albicans morphogenesis, and identified functional divergence of complex members. We observed that C. albicans Mss11 was dispensable for filamentation, and that overexpression of FLO8 caused constitutive filamentation even in the absence of Mfg1. Epistasis experiments suggested that Mfg1 acts downstream of protein kinase A, as does Flo8. Harnessing transcriptional profiling and chromatin immunoprecipitation coupled to microarray analysis, we identified divergence between transcriptional targets of Mfg1 and Flo8 in C. albicans. A key direct transcriptional target of Mfg1 is TEC1, for which overexpression was sufficient to restore filamentation in the absence of Mfg1. To identify additional Mfg1 downstream effectors, we employed a novel strategy to select for mutations that restore filamentation in the absence of Mfg1. Whole genome sequencing of filamentation-competent mutants revealed chromosome 6 amplification as a conserved adaptive mechanism. A key determinant of the amplification on chromosome 6 is FLO8, as deletion of one allele blocked morphogenesis, and chromosome 6 was not amplified in evolved lineages for which FLO8 was re-located to a different chromosome. Thus, this work highlights rewiring of key morphogenetic regulators over evolutionary time and aneuploidy as an adaptive mechanism driving fungal morphogenesis.
2018-07-24 | GSE117477 | 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.
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:The Spt-Ada-Gcn5-acetyltransferase (SAGA) chromatin-modifying complex is a transcriptional coactivator that contains four different modules of subunits. The intact SAGA complex has been well characterized for its function in transcription regulation and development. However, little is known about the roles of individual modules within SAGA and if they have any SAGA independent functions. Here we demonstrate that the two enzymatic modules of Drosophila SAGA are differently required in oogenesis. Ada2b is part of the HAT module (Histone Acetyl Transferase), whereas Ataxin-7 and non-stop are members of the DUB module (Deubiquitinase). Loss of the HAT activity blocks oogenesis, while loss of the DUB activity does not. However, the DUB module regulates a subset of genes in early embryogenesis and loss of the DUB subunits causes defects in embryogenesis. ChIP-seq analysis of ada2b, spt3, nonstop, and sgf11revealed that both the DUB and HAT modules bind most SAGA target genes even though many of these targets do not require the DUB module for expression. Furthermore, we found that the DUB module can bind to chromatin and regulate transcription independently of the rest of SAGA. Our results suggest that the DUB module has functions within SAGA as well as independent functions.
2017-10-01 | GSE98864 | GEO
Project description:We have analyzed the global effect of the conserved transcription-mRNA export factor Sus1 on transcription and its association with chromatin. We used genomic run-on experiments to show that Sus has a broad impact on the stability of most RNA polymerase II-transcribed genes. Genome association of Sus1 by the chromatin immunoprecipitation technique showed that Sus1 was widely distributed throughout coding regions, tending to accumulate towards the 3â ends of highly transcribed transcription factor IID (TFIID) and Spt-Ada-Gcn5 acetyltransferase (SAGA) dependent genes. This accumulation depends on growth conditions, the transcriptional rate and whether the genes are TFIID- or SAGA-regulated. Validation of Sus1 occupancy data also revealed that Sus1 appears at tRNAs. Concomitantly, deletion of SUS1 leads to tRNA overexpression. In addition, we discovered that distinctive SAGA subunits Spt8 and Spt7 play a key role in Sus1 enrichment at the 3â ends of SAGA-regulated genes upon temperature shift and at tRNAs. Thus, our study identifies the molecular mechanisms by which a SAGA factor is recruited genome-wide, and provides evidence of a more general role for this conserved coactivator in eukaryotic transcription. Genome wide analysis of Sus1 in wild type and Spt7 and Spt8 deletion mutants using ChIP-exo and genomic run-on experiments
2016-05-15 | E-GEOD-65902 | biostudies-arrayexpress
Project description:The Spt-Ada-Gcn5-acetyltransferase (SAGA) chromatin-modifying complex is a transcriptional coactivator that contains four different modules of subunits. The intact SAGA complex has been well characterized for its function in transcription regulation and development. However, little is known about the roles of individual modules within SAGA and if they have any SAGA independent functions. Here we demonstrate that the two enzymatic modules of Drosophila SAGA are differently required in oogenesis. Loss of the HAT activity blocks oogenesis, while loss of the DUB activity does not. However, the DUB module regulates a subset of genes in early embryogenesis and loss of the DUB subunits causes defects in embryogenesis. ChIP-seq analysis of ada2b, spt3, nonstop, and sgf11revealed that both the DUB and HAT modules bind most SAGA target genes even though many of these targets do not require the DUB module for expression. Furthermore, we found that the DUB module can bind to chromatin and regulate transcription independently of the rest of SAGA. Our results suggest that the DUB module has functions within SAGA as well as independent functions.
2017-10-01 | GSE98862 | GEO
Project description:The SAGA (Spt-Ada-Gcn5 acetyltransferase) complex is an evolutionarily conserved, multifunctional co-activator complex, which has a critical role in histone acetylation, gene expression, and various developmental processes in eukaryotes. However, little is known about the composition and function of the SAGA complex in plants. Here, we found that the SAGA complex in Arabidopsis thaliana contains not only conserved subunits and but also four plant-specific subunits, including three homologous subunits, SCS1, SCS2A, and SCS2B (SCS1/2A/2B), and a TAF-like subunit, TAFL. We also found that a series of SAGA subunits are shared in yeast and/or metazoans but are absent in Arabidopsis. Mutations in the unique SAGA subunits SCS1/2A/2B lead to defective phenotypes similar to those caused by mutations in the conserved SAGA subunits HAG1 and ADA2B; these defective phenotypes include delayed juvenile-to-adult phase transition, late flowering, and increased trichome density. SCS1/2A/2B function in the SAGA complex to promote the transcription of development-related genes by facilitating histone H3 acetylation. The results suggest that, compared to SAGA complexes in other eukaryotes, the SAGA complex in plants has evolved unique features that are necessary for normal growth and development.
2021-04-11 | GSE161546 | GEO
Project description:The SAGA (Spt-Ada-Gcn5 acetyltransferase) complex is an evolutionarily conserved, multifunctional co-activator complex, which has a critical role in histone acetylation, gene expression, and various developmental processes in eukaryotes. However, little is known about the composition and function of the SAGA complex in plants. Here, we found that the SAGA complex in Arabidopsis thaliana contains not only conserved subunits and but also four plant-specific subunits, including three homologous subunits, SCS1, SCS2A, and SCS2B (SCS1/2A/2B), and a TAF-like subunit, TAFL. We also found that a series of SAGA subunits are shared in yeast and/or metazoans but are absent in Arabidopsis. Mutations in the unique SAGA subunits SCS1/2A/2B lead to defective phenotypes similar to those caused by mutations in the conserved SAGA subunits HAG1 and ADA2B; these defective phenotypes include delayed juvenile-to-adult phase transition, late flowering, and increased trichome density. SCS1/2A/2B function in the SAGA complex to promote the transcription of development-related genes by facilitating histone H3 acetylation. The results suggest that, compared to SAGA complexes in other eukaryotes, the SAGA complex in plants has evolved unique features that are necessary for normal growth and development.
2021-04-11 | GSE161545 | GEO