Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

The transcriptional repressor Ssn6 modulates phase separation to regulate fungal gene expression

ABSTRACT: The transcriptional regulation of cell fate plays a central role in eukaryotic cell differentiation. In the human fungal pathogen Candida albicans, the white-to-opaque switch is controlled by a network of eight transcription factors (TFs). These include Ssn6, a negative regulator of the opaque state that can function with its co-repressor Tup1, and together these form a global repressor complex that is conserved from yeast to mammals. Here, we evaluated the roles of four Ssn6 domains (N, TPR, M, and CTD) in white-opaque switching. Loss of the prion-like N or M domains had limited effects on Ssn6 phenotypes. In contrast, the TPR (tetratricopeptide repeat) domain was critical for function, consistent with this domain mediating interactions with Tup1 and DNA-binding TFs. The intrinsically disordered C-terminal domain (CTD) showed complex roles; deletion of this domain increased Ssn6 activity while substitution of acidic residues within this region abolished Ssn6 function. Notably, these phenotypes were linked to the phase separation capacity of Ssn6, as changes to the TPR or CTD altered the properties of Ssn6 condensates in human U2OS cells. Experiments using purified Ssn6 (+/-Tup1) demonstrated that this protein is recruited into condensates formed by other white-opaque-regulating TFs and alters condensate properties in a TPR- and CTD-dependent manner. Together, these observations reveal how individual Ssn6 domains can modulate the phase separation properties of DNA-binding TFs and thereby regulate gene expression and cell fate.

ORGANISM(S): Candida albicans

PROVIDER: GSE319560 | GEO | 2026/02/17

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Ssn6 defines a new level of regulation of white-opaque switching in Candida albicans and is required for the stochasticity of the switch

Project description:The human commensal and opportunistic pathogen Candida albicans can switch between two distinct, heritable cell types, named “white” and “opaque,” which differ in morphology, mating abilities, metabolic preferences, and in their interactions with the host immune system. Previous studies revealed a highly interconnected group of transcriptional regulators that control switching between the two cell types. Here, we identify Ssn6, the C. albicans functional homolog of the Saccharomyces cerevisiae transcriptional co-repressor Cyc8, as a new regulator of white-opaque switching. In a or α mating type strains, deletion of SSN6 results in mass switching from the white to the opaque cell type. Transcriptional profiling of ssn6 deletion mutant strains reveals that Ssn6 represses part of the opaque cell transcriptional program in white cells and the majority of the white cell transcriptional program in opaque cells. Genome-wide chromatin immunoprecipitation experiments demonstrate that Ssn6 is tightly integrated into the opaque cell regulatory circuit and that the positions to which it is bound across the genome strongly overlap with those bound by Wor1 and Wor2, previously identified regulators of white-opaque switching. This work reveals the next layer in the white-opaque transcriptional circuitry by integrating a transcriptional regulator that does not bind DNA directly but instead associates with specific combinations of DNA-bound transcriptional regulators.

2015-12-28 | GSE74011 | GEO

The stress response factors Yap6, Cin5, Phd1, and Skn7 direct targeting of the conserved co-repressor Tup1-Ssn6

Project description:The budding yeast transcriptional corepressor Tup1-Ssn6 is a model for studying similar repressosome complexes in multicellular eukaryotes. Tup1-Ssn6 does not bind DNA directly, but is directed to individual promoters by one or more DNA-binding proteins, referred to as Tup1 recruiters. We determined the genomic distribution of Tup1 and Ssn6 by ChIP-chip and found that most loci bound by Tup1-Ssn6 could not be explained by co-occupancy with a known recruiting cofactor. Furthermore, we found that individual deletions of known Tup1 recruiters did not significantly alter Tup1 binding profile. These two observations suggest that Tup1 recruitment typically depends on multiple recruiting cofactors, and that new Tup1 recruiting proteins remain to be discovered. To identify new recruiting proteins we computationally screened for factors with binding patterns similar to the observed Tup1-Ssn6 genomic distribution. Four top candidates, Cin5, Skn7, Phd1, and Yap6, all known to be associated with stress response gene regulation, were experimentally confirmed to physically interact with Tup1 and/or Ssn6. Incorporating these new cofactors with previously characterized cofactors now accounts for the majority of Tup1 binding across the genome, and expands our understanding of the mechanism by which Tup1-Ssn6 is directed to its targets.

2011-03-01 | GSE26311 | GEO

Global Regulation of Nucleosome Organization And Transcription By The Yeast Ssn6-Tup1 Corepressor (expression)

Project description:The yeast Ssn6-Tup1 complex regulates gene expression through a variety of mechanisms, including positioning of nucleosomes over promoters of some target genes to limit accessibility to the transcription machinery. To further define the functions of Ssn6-Tup1 in gene regulation and chromatin remodeling, we performed genome-wide profiling of changes in nucleosome organization and gene expression that occur upon loss of SSN6 or TUP1, and observed extensive nucleosome alterations in both promoters and gene bodies of derepressed genes. Our improved nucleosome profiling and analysis approaches revealed low-occupancy promoter nucleosomes (P nucleosomes) at locations previously defined as nucleosome-free regions. In the absence of SSN6 or TUP1, this P nucleosome is frequently lost, whereas nucleosomes are gained at -1 and +1 positions, accompanying up-regulation of downstream genes. Our analysis of public ChIP-seq data revealed that Ssn6 and Tup1 preferentially bind TATA-containing promoters, which are also enriched in genes derepressed upon loss of SSN6 or TUP1. These results suggest that stabilization of the P nucleosome on TATA-containing promoters may be a central feature of the repressive chromatin architecture created by the Ssn6-Tup1 corepressor, and that releasing the P nucleosome contributes to gene activation.

2012-10-10 | GSE37466 | GEO

Global Regulation of Nucleosome Organization And Transcription By The Yeast Ssn6-Tup1 Corepressor (MNase-Seq)

2012-10-10 | GSE37465 | GEO

The stress response factors Yap6, Cin5, Phd1, and Skn7 direct targeting of the conserved co-repressor Tup1-Ssn6

2011-03-01 | E-GEOD-26311 | biostudies-arrayexpress

Global Regulation of Nucleosome Organization And Transcription By The Yeast Ssn6-Tup1 Corepressor (MNase-Seq)

2012-10-10 | E-GEOD-37465 | biostudies-arrayexpress

Global Regulation of Nucleosome Organization And Transcription By The Yeast Ssn6-Tup1 Corepressor (expression)

2012-10-10 | E-GEOD-37466 | biostudies-arrayexpress

Global Regulation of Nucleosome Organization And Transcription By The Yeast Ssn6-Tup1 Corepressor

Project description:This SuperSeries is composed of the following subset Series: GSE37465: Global Regulation of Nucleosome Organization And Transcription By The Yeast Ssn6-Tup1 Corepressor (MNase-Seq) GSE37466: Global Regulation of Nucleosome Organization And Transcription By The Yeast Ssn6-Tup1 Corepressor (expression) Refer to individual Series

2012-10-10 | E-GEOD-37467 | biostudies-arrayexpress

Transcription profiling by array of Candida albicans tup1, nrg1 and ssn6 mutants

Project description:Profilings of the Candida albicans mutant: tup1, nrg1, ssn6 (smooth and wrinkled phenotypes)

2010-05-14 | E-MEXP-1217 | biostudies-arrayexpress

Ssn6, a new regulator of white-opaque switching in Candida albicans

Project description:The human fungal pathogen Candida albicans can switch between two phenotypic cell types, termed “white” and “opaque.” Both cell types are heritable for many generations, and the switch between the two types occurs epigenetically, that is, without a change in the DNA sequence of the genome. In this work we describe that SSN6, the C. albicans functional homolog of Saccharomyces cerevisiae Cyc8, is a regulator of the white-opaque switch. Chromatin IP's were performed using the protocol described by Hernday et al (Methods Enzymol. 2010;470:737-58. ). Briefly, log phase cultures were crosslinked with formaldehyde prior to cell lysis, chromatin shearing, and transcription-factor immunoprecipitation. Recovered DNA was amplified, dye-coupled, and competitively hybridized to a 244k-probe tiling array with a non-enriched genomic DNA reference.

2014-06-30 | GSE58054 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data