Saccharomyces cerevisiae
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA381711 | ENA |
REPOSITORIES: ENA
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Project description:In eukaryotes, a dynamic ribonucleic protein machine known as the spliceosome catalyzes the removal of introns from pre-messenger RNA (pre-mRNA). Recent studies show the process of RNA-synthesis and RNA-processing to be spatio-temporally coordinated, indicating that RNA splicing takes place in the context of chromatin. H2A.Z is a highly conserved histone variant of the canonical histone H2A. In S. cerevisiae, H2A.Z is deposited into chromatin by the SWR1-complex, is found near the 5’ ends of protein-coding genes, and has been implicated in transcription regulation. Here we show that splicing of intron-containing genes in cells lacking H2A.Z is impaired, particularly under suboptimal splicing conditions. Cells lacking H2A.Z are especially dependent on a functional U2 snRNP, as H2A.Z shows extensive genetic interactions with U2 snRNP associated proteins, and RNA-seq reveals introns with non-consensus branch points are particularly sensitive to H2A.Z loss. Consistently, H2A.Z promotes efficient spliceosomal rearrangements involving the U2 snRNP, as H2A.Z loss results in persistent U2 snRNP association and decreased recruitment of downstream snRNPs to nascent RNA. H2A.Z impairs transcription elongation, suggesting that spliceosome rearrangements are tied to H2A.Z’s role in elongation. Depletion of disassembly factor Prp43 suppresses H2A.Z-mediated splice defects, indicating that, in the absence of H2A.Z, stalled spliceosomes are disassembled and unspliced RNAs are released. Together these data demonstrate that H2A.Z is required for efficient pre-mRNA splicing and indicate a role for H2A.Z in coordinating the kinetics of transcription elongation and splicing.
2017-05-18 | GSE97416 | GEO
Project description:Multiple lines of evidence implicate chromatin in the regulation of pre-mRNA splicing. However, the influence of chromatin factors on co-transcriptional splice-site usage remains unclear. Here we investigated the function of the highly conserved histone variant H2A.Z in pre-mRNA splicing using the intron-rich model yeast, Schizosaccharomyces pombe. Using Epistatic Mini-Array Profiles (EMAPs) to survey the genetic interaction landscape of the Swr1 nucleosome remodeling complex, which deposits H2A.Z, we uncovered evidence for functional interactions with components of the spliceosome. In support of these genetic connections, splicing-specific microarrays show that H2A.Z and the Swr1 ATPase are required during temperature stress for the efficient splicing of a sub-set of introns. Notably, affected introns are enriched for H2A.Z occupancy, and more likely to contain non-consensus splice sites. To test the significance of the latter correlation, we mutated the splice sites in an affected intron to consensus and found this suppressed the requirement for H2A.Z in splicing of that intron. These data suggest that H2A.Z occupancy promotes co-transcriptional splicing of sub-optimal introns that may otherwise be discarded via proofreading ATPases. Consistent with this model, we show that over-expression of splicing ATPase Prp16 suppresses both the growth and splicing defects seen in the absence of H2A.Z.
2017-08-22 | GSE97983 | GEO
Project description:Multiple lines of evidence implicate chromatin in the regulation of pre-mRNA splicing. However, the influence of chromatin factors on co-transcriptional splice-site usage remains unclear. Here we investigated the function of the highly conserved histone variant H2A.Z in pre-mRNA splicing using the intron-rich model yeast, Schizosaccharomyces pombe. Using Epistatic Mini-Array Profiles (EMAPs) to survey the genetic interaction landscape of the Swr1 nucleosome remodeling complex, which deposits H2A.Z, we uncovered evidence for functional interactions with components of the spliceosome. In support of these genetic connections, splicing-specific microarrays show that H2A.Z and the Swr1 ATPase are required during temperature stress for the efficient splicing of a sub-set of introns. Notably, affected introns are enriched for H2A.Z occupancy, and more likely to contain non-consensus splice sites. To test the significance of the latter correlation, we mutated the splice sites in an affected intron to consensus and found this suppressed the requirement for H2A.Z in splicing of that intron. These data suggest that H2A.Z occupancy promotes co-transcriptional splicing of sub-optimal introns that may otherwise be discarded via proofreading ATPases. Consistent with this model, we show that over-expression of splicing ATPase Prp16 suppresses both the growth and splicing defects seen in the absence of H2A.Z.
2017-08-22 | GSE97982 | GEO
Project description:The histone variant H2A.Z promotes splicing of weak introns
| PRJNA383570 | ENA
Project description:The histone variant H2A.Z promotes splicing of weak introns (array)
| PRJNA383571 | ENA
Project description:Among the collection of chromatin modifications that influence its function and structure, the substitution of canonical histones by the so-called histone variants is one of the most prominent actions. Since crucial meiotic transactions are modulated by chromatin, here we investigate the functional contribution of the H2A.Z histone variant during both unperturbed meiosis and upon challenging conditions where the meiotic recombination checkpoint is triggered in budding yeast by the absence of the synaptonemal complex component Zip1. We have found that H2A.Z localizes to meiotic chromosomes in an SWR1-dependent manner. Although meiotic recombination is not substantially altered, the htz1 mutant (lacking H2A.Z) shows slower meiotic progression, impaired sporulation and reduced spore viability. These phenotypes are likely accounted for by the misregulation of meiotic gene expression landscape observed in htz1. In the zip1 mutant, the absence of H2A.Z results in a tighter meiotic arrest imposed by the meiotic recombination checkpoint. We have found that Mec1-dependent Hop1-T318 phosphorylation and the ensuing Mek1 activation are not significantly altered in zip1 htz1; however, downstream checkpoint targets, such as the meiosis I-promoting factors Ndt80, Cdc5 and Clb1, are drastically down-regulated. The study of the checkpoint response in zip1 htz1 has also allowed us to reveal the existence of an additional function of the Swe1 kinase, independent of CDK inhibitory phosphorylation, which is relevant to restrain meiotic cell cycle progression. In summary, our study shows that the H2A.Z histone variant impacts various aspects of meiotic development adding further insight into the relevance of chromatin dynamics for accurate gametogenesis.
2018-02-02 | GSE110022 | GEO
Project description:The histone variant H2A.Z promotes splicing of weak introns (ChIP-Seq)
| PRJNA383572 | ENA
Project description:Functional impact of the H2A.Z histone variant during meiosis in Saccharomyces cerevisiae
| PRJNA432577 | ENA
Project description:Pre-mRNA splicing is vital for the proper function and regulation of eukaryotic gene expression. Saccharomyces cerevisiae has been used as a model organism for studies of RNA splicing because of the striking conservation of the spliceosome and its catalytic activity. Nonetheless, there are relatively few annotated alternative splice forms, particularly when compared to higher eukaryotes. Here, we describe a method to combine large scale RNA sequencing data to accurately discover novel splice isoforms in Saccharomyces cerevisiae. Using our method, we find extensive evidence for novel splicing of annotated intron-containing genes as well as genes without previously annotated introns and splicing of transcripts that are antisense to annotated genes. By incorporating several mutant strains at varied temperatures, we find conditions which lead to differences in alternative splice form usage. Despite this, every class and category of alternative splicing we find in our datasets is found, often at lower frequency, in wildtype cells under normal growth conditions. Together, these findings show that there is widespread splicing in Saccharomyces cerevisiae.
2024-05-01 | GSE120497 | GEO
Project description:Positioned nucleosomes limit the access of proteins to DNA and implement regulatory features encoded in eukaryotic genomes. Here we generated the first genome-wide nucleosome positioning map for Schizosaccharomyces pombe and annotated transcription start and termination sites genome-wide. Using this resource we found surprising differences compared to the nucleosome organization in the distantly related yeast Saccharomyces cerevisiae [the cerevisiae data has been published by others (PMID: 17873876) and the raw data is deposited at ArrayExpress(E-MEXP-1172)]. DNA sequence guides nucleosome positioning differently, e.g., poly(dA:dT) elements are not enriched in S. pombe nucleosome-depleted regions (NDRs). Regular nucleosomal arrays emanate more asymmetrically, i.e., mainly co-directionally with transcription, from promoter NDRs, but promoters harbouring the histone variant H2A.Z show regular arrays also upstream. Regular nucleosome phasing in S. pombe has a very short repeat length of 154 base pairs, and requires a remodeler, Mit1, conserved in humans but not found in S. cerevisiae. Nucleosome positioning mechanisms are evidently not universal but evolutionarily plastic.
2010-02-01 | GSE16040 | GEO