Saccharomyces cerevisiae
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA265882 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:The disruption of chromatin structure can result in transcription initiation from cryptic promoters within gene bodies. While the passage of RNA polymerase II is a well-characterized chromatin-disrupting force, numerous factors, including histone chaperones, normally stabilize chromatin on transcribed genes, thereby repressing cryptic transcription. DNA replication, which requires a partially overlapping set of histone chaperones, is also inherently disruptive to chromatin, but a role for DNA replication in cryptic transcription has never been examined. In this study, we tested the hypothesis that, in the absence of chromatin-stabilizing factors, DNA replication can promote cryptic transcription in S. cerevisiae. Using a novel fluorescent reporter assay, we show that multiple factors, including Asf1, CAF-1, Rtt106, Spt6, and FACT, block transcription from a cryptic promoter, but are entirely or partially dispensable in G1-arrested cells, suggesting a requirement for DNA replication in chromatin disruption. Collectively, these results demonstrate that transcription fidelity is dependent on numerous factors that function to assemble chromatin on nascent DNA.
2023-12-07 | GSE249580 | GEO
Project description:The disruption of chromatin structure can result in transcription initiation from cryptic promoters within gene bodies. While the passage of RNA polymerase II is a well-characterized chromatin-disrupting force, numerous factors, including histone chaperones, normally stabilize chromatin on transcribed genes, thereby repressing cryptic transcription. DNA replication, which requires a partially overlapping set of histone chaperones, is also inherently disruptive to chromatin, but a role for DNA replication in cryptic transcription has never been examined. In this study, we tested the hypothesis that, in the absence of chromatin-stabilizing factors, DNA replication can promote cryptic transcription in S. cerevisiae. Using a novel fluorescent reporter assay, we show that multiple factors, including Asf1, CAF-1, Rtt106, Spt6, and FACT, block transcription from a cryptic promoter, but are entirely or partially dispensable in G1-arrested cells, suggesting a requirement for DNA replication in chromatin disruption. Collectively, these results demonstrate that transcription fidelity is dependent on numerous factors that function to assemble chromatin on nascent DNA.
2023-12-06 | GSE249469 | GEO
Project description:H2A.Z is a highly conserved histone variant involved in several key nuclear processes. It is incorporated into promoters by SWR-C-related chromatin remodeling complexes, but whether it is also actively excluded from non-promoter regions is not clear. Here, we provide genomic and biochemical evidence that RNA polymerase II (RNAPII) elongation-associated histone chaperones FACT and Spt6 both contribute to restricting H2A.Z from intragenic regions. In the absence of FACT or Spt6, the lack of H2A.Z eviction, coupled to its pervasive incorporation by mislocalized SWR-C, alters chromatin composition and contributes to cryptic initiation. Thus, chaperone-mediated H2A.Z removal is crucial for restricting the chromatin signature of gene promoters, which otherwise may license or promote cryptic transcription. We profiled H2A.Z occupancy in S. cerevisiae by ChIP-chip on tiling arrays in different mutants for chromatin remodelers and histone chaperones. In most experiments, H2A.Z ChIP samples (Cy5-labeled) were performed using a polyclonal antibody against H2A.Z and hybridized against H2B ChIP samples (Cy3-labeled), also performed using a polyclonal antibody. Temperature-sensitive mutants for the histone chaperones Spt16 and Spt6 (spt16-197 and spt6-1004 respectively) showed strong H2A.Z localization defects so the role of these factors in H2A.Z localization was further analyzed. H2A.Z ChIP-chip experiments in spt16-197 and spt6-1004 were repeated using different experimental designs [normalized against Input DNA or Mock (IgG) ChIP samples]. The contribution of Spt16 and Spt6 on H2A.Z localization was also confirmed by nuclear depletion of Spt16 and Spt6 using the anchor-away system. H2A.Z ChIP-chip experiments were also performed in sic1Δ and spt16-197/sic1Δ cells in order to rule out any G1-arrest artifact. H2A.Z ChIP-chip experiments were repeated using spike-in controls for normalization, revealing widespread H2A.Z occupancy in Spt16 and Spt6 mutants. In addition, the localization of the chromatin remodeler SWR-C was determined in wild type cells as well as in spt16-197 and spt6-1004 cells. Finally, we also profiled histone H4 occupancy by ChIP-chip in wild type, spt16-197, spt6-1004, spt16-197/htz1Δ and spt6-1004/htz1Δ cells. All ChIP-chip experiments were done in duplicates. Each microarray was normalized using the Lima Loess and replicates were combined using a weighted average method as previously described (Pokholok et al., 2005).
2015-05-12 | E-GEOD-62880 | biostudies-arrayexpress
Project description:H2A.Z is a highly conserved histone variant involved in several key nuclear processes. It is incorporated into promoters by SWR-C-related chromatin remodeling complexes, but whether it is also actively excluded from non-promoter regions is not clear. Here, we provide genomic and biochemical evidence that RNA polymerase II (RNAPII) elongation-associated histone chaperones FACT and Spt6 both contribute to restricting H2A.Z from intragenic regions. In the absence of FACT or Spt6, the lack of H2A.Z eviction, coupled to its pervasive incorporation by mislocalized SWR-C, alters chromatin composition and contributes to cryptic initiation. Thus, chaperone-mediated H2A.Z removal is crucial for restricting the chromatin signature of gene promoters, which otherwise may license or promote cryptic transcription.
2015-05-12 | GSE62880 | GEO
Project description:Transcription can be quite disruptive for chromatin so cells have evolved mechanisms to preserve chromatin integrity during transcription, hence preventing the emergence of cryptic transcript from spurious promoter sequences. How these transcripts are regulated and processed by cells remains poorly characterized. Notably, very little is known about the termination of cryptic transcription. Here we used RNA-Seq to identify and characterize cryptic transcripts in Spt6 mutant cells (spt6-1004) in Saccharomyces cerevisiae. We found polyadenylated cryptic transcripts running both sense and anti-sense relative to genes in this mutant. Cryptic promoters were enriched for TATA boxes, suggesting that the underlying DNA sequence defines the location of cryptic promoters. While intragenic sense cryptic transcripts terminate at the terminator of the genes that host them, we found that anti-sense cryptic transcripts preferentially terminate at the 3’-end of upstream genes. These findings led us to demonstrate that most terminators in yeast are bidirectional, leading to termination and polyadenylation of transcripts coming from either direction. We propose that S. cerevisiae has evolved this mechanism in order to prevent spurious transcription from invading neighbouring genes, a feature particularly critical for organisms with small compact genomes.
2017-04-03 | GSE89601 | GEO
Project description:Microarray analysis was used to identify all cryptic promoters in the S. cerevisiae genome that are activated in spt6 and spt16 mutants. These experiments showed that cryptic initiation is widespread, occurring in approximately 1,000 genes. We generated 2 microarray profiles from fluor-reversed replicates of wild-type and spt6-1004 or spt16-197 mutants. See Cheung et al., (2008) in revision.
2010-05-16 | E-GEOD-12272 | biostudies-arrayexpress
Project description:Microarray analysis was used to identify all cryptic promoters in the S. cerevisiae genome that are activated in spt6 and spt16 mutants. These experiments showed that cryptic initiation is widespread, occurring in approximately 1,000 genes.
2008-11-14 | GSE12272 | GEO
Project description:Spatial regulation of transcription and histone occupancy by histone chaperones FACT and Spt6
| PRJNA286077 | ENA
Project description:Bidirectional terminators in Saccharomyces cerevisiae prevent cryptic transcription from invading neighbouring genes
| PRJNA352693 | ENA
Project description:H2A.Z acetylation fine-tunes gene expression dynamics by regulating H2A.Z degradation
| PRJNA382973 | ENA