Saccharomyces cerevisiae
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ABSTRACT:
PROVIDER: PRJNA103817 | ENA |
REPOSITORIES: ENA
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Project description:ESA1 (essential SAS-family acetyltransferase) is the only known yeast histone acetyltransferase (HAT) required for cell viability. It is a member of the MYST (MOZ, YBF2/SAS3, SAS2, Tip60) family of HAT proteins and contains a conserved acetyltransferase domain in addition to a chromodomain. While ESA1âs HAT activity is important in processes such as deoxyribonucleic acid (DNA) repair, acetylation is likely not its essential function. Our lab has shown that mutants with a single point mutation in the active site cysteine are still viable even though their acetyltransferase abilities are abolished. Furthermore, chromatin immunoprecipitation assays have shown ESA1 distributed evenly along the length of chromatin, not localized to specific promoters as would be expected from a HAT protein involved in transcriptional regulation. As is the case for other HAT proteins, ESA1âs acetyltransferase activity is significant, but in processes such as DNA replication, DNA repair and cell cycle progression. The aim of this project is to determine the essential function of ESA1 - the catalytic subunit of the yeast HAT complex, NuA4 (nucleosome acetyltransferase of H4) â using a bypass suppression screen to identify suppressors of ESA1. It is proposed that suppressing mutations will alter a gene involved in the process that is the essential function of ESA1. Thus, identifying a suppressor that can bypass the need for ESA1 may provide insight into its essential function. Since ESA1 is an essential gene, a haploid esa1â strain in which wild-type ESA1 is provided on a centromeric plasmid was utilized. The bypass suppression screen resulted in suppressors of ESA1 that allowed esa1â cells to be viable even in the absence of the essential gene. These second site suppressors (sup-) of ESA1 each show the Mendelian segregation pattern of the suppressing gene and ESA1 in 2:2 ratios, implying they are single genes unlinked to ESA1. Microarray and nuclear morphology studies show abnormal gene expression and morphology of the esa1ï sup- cells, further implicating the suppressing mutation in DNA repair and replication processes. Investigating ESA1âs essential role and a probable conservation of function across species can provide a deeper understanding of the capabilities of HAT complexes. Experiment Overall Design: Eight samples were analyzed. The only variables are the ESA1 and SUP2 genes. WT (ESA1 SUP2), 2 replicates. Single mutant (ESA1 sup2-), 3 replicates. Double mutant (esa1 sup2-), 3 replicates.
2008-06-16 | E-GEOD-9840 | biostudies-arrayexpress
Project description:ESA1 (essential SAS-family acetyltransferase) is the only known yeast histone acetyltransferase (HAT) required for cell viability. It is a member of the MYST (MOZ, YBF2/SAS3, SAS2, Tip60) family of HAT proteins and contains a conserved acetyltransferase domain in addition to a chromodomain. While ESA1’s HAT activity is important in processes such as deoxyribonucleic acid (DNA) repair, acetylation is likely not its essential function. Our lab has shown that mutants with a single point mutation in the active site cysteine are still viable even though their acetyltransferase abilities are abolished. Furthermore, chromatin immunoprecipitation assays have shown ESA1 distributed evenly along the length of chromatin, not localized to specific promoters as would be expected from a HAT protein involved in transcriptional regulation. As is the case for other HAT proteins, ESA1’s acetyltransferase activity is significant, but in processes such as DNA replication, DNA repair and cell cycle progression. The aim of this project is to determine the essential function of ESA1 - the catalytic subunit of the yeast HAT complex, NuA4 (nucleosome acetyltransferase of H4) – using a bypass suppression screen to identify suppressors of ESA1. It is proposed that suppressing mutations will alter a gene involved in the process that is the essential function of ESA1. Thus, identifying a suppressor that can bypass the need for ESA1 may provide insight into its essential function. Since ESA1 is an essential gene, a haploid esa1∆ strain in which wild-type ESA1 is provided on a centromeric plasmid was utilized. The bypass suppression screen resulted in suppressors of ESA1 that allowed esa1∆ cells to be viable even in the absence of the essential gene. These second site suppressors (sup-) of ESA1 each show the Mendelian segregation pattern of the suppressing gene and ESA1 in 2:2 ratios, implying they are single genes unlinked to ESA1. Microarray and nuclear morphology studies show abnormal gene expression and morphology of the esa1- sup- cells, further implicating the suppressing mutation in DNA repair and replication processes. Investigating ESA1’s essential role and a probable conservation of function across species can provide a deeper understanding of the capabilities of HAT complexes. Keywords: Comparison of strains lacking essential ESA1 gene to those containing an ESA1 bypass suppressor.
2007-12-12 | GSE9840 | GEO
Project description:Spn1/Iws1 is an essential eukaryotic transcription elongation factor that is conserved from yeast to humans. Several studies have shown that Spn1 functions as a histone chaperone to control transcription, RNA splicing, genome stability, and histone modifications as an integral member of the RNA polymerase II elongation complex. However, the precise role of Spn1 is not understood, and there is little understanding of why it is essential for viability. To address these issues, we have isolated eight suppressor mutations that bypass the essential requirement for Spn1 in Saccharomyces cerevisiae. Unexpectedly, the suppressors identify several functionally distinct complexes and activities, including the histone chaperone FACT, the histone methyltransferase Set2, the Rpd3S histone deacetylase complex, the histone acetyltransferase Rtt109, the nucleosome remodeler Chd1, and a member of the SAGA co-activator complex, Sgf73. The identification of these distinct groups and their analysis suggests that there are multiple mechanisms by which Spn1 bypass can occur, including changes in histone acetylation and alterations of other histone chaperones. Thus, Spn1 may participate in multiple functions during transcription. Our results suggest that bypass of a subset of these functions allows viability in the absence of Spn1.
2022-05-16 | GSE202590 | GEO
Project description:Histone post-translational modifications (PTMs) are critical for processes such as transcription. The more notable among these are the non-acetyl histone lysine acylation modifications such as crotonylation, butyrylation and succinylation. However, the biological relevance of these PTMs is not fully understood because their regulation is largely unknown. Here, we set out to investigate whether the main histone acetyltransferases in budding yeast, Gcn5 and Esa1, possess crotonyltransferase activity. In vitro studies revealed that the Gcn5-Ada2-Ada3 (ADA) and Esa1-Yng2-Epl1 (Piccolo NuA4) histone acetyltransferase complexes have the capacity to crotonylate histones. Mass spectrometry analysis revealed that ADA and Piccolo NuA4 crotonylate lysines in the N-terminal tails of histone H3 and H4, respectively. Functionally, we show that crotonylation selectively affects gene transcription in vivo in a manner dependent on Gcn5 and Esa1. Thus, we identify the Gcn5- and Esa1-containing ADA and Piccolo NuA4 complexes as bona fide crotonyltransferases that promote crotonylation-dependent transcription.
2019-11-06 | PXD015488 | Pride
Project description:Evidence suggests that the TAF1 subunit of TFIID is a histone acetyltransferase (HAT) that is functionally redundant with the Gcn5 HAT of the SAGA and ADA complexes. Here we test a number of predictions of this hypothesis by examining the in vivo histone acetylation targets of TAF1 and Gcn5, and re-examining the basis for the reported genome-wide functional redundancy between TAF1 and Gcn5. Our findings do not support a number of basic tenets of the hypothesis, thus bringing into question the physiological presence of any TAF1 HAT function in yeast. We have also conducted genome-wide expression profiles of numerous other HATs (Elp3, Hat1, Hpa2, Sas3) in an effort identify potential functional redundancy between TAF1 and other HATs, and find none. Further investigation of TAF1 and the Esa1 HAT re-affirm a link between histone H4 acetylation by Esa1, and TFIID binding via interactions with acetylated histone H4-binding protein Bdf1. Keywords: genetic modification
2006-03-20 | GSE3345 | GEO
Project description:Evidence suggests that the TAF1 subunit of TFIID is a histone acetyltransferase (HAT) that is functionally redundant with the Gcn5 HAT of the SAGA and ADA complexes. Here we test a number of predictions of this hypothesis by examining the in vivo histone acetylation targets of TAF1 and Gcn5, and re-examining the basis for the reported genome-wide functional redundancy between TAF1 and Gcn5. Our findings do not support a number of basic tenets of the hypothesis, thus bringing into question the physiological presence of any TAF1 HAT function in yeast. We have also conducted genome-wide expression profiles of numerous other HATs (Elp3, Hat1, Hpa2, Sas3) in an effort identify potential functional redundancy between TAF1 and other HATs, and find none. Further investigation of TAF1 and the Esa1 HAT re-affirm a link between histone H4 acetylation by Esa1, and TFIID binding via interactions with acetylated histone H4-binding protein Bdf1. Keywords: ChIP-chip, genetic modification
2006-03-20 | GSE3346 | GEO
Project description:Enzymes that modify and remodel chromatin are subunits in broadly conserved macromolecular complexes. One key chromatin modification is the dynamic acetylation of histones by opposing activities of acetyltransferase and deacetylase complexes. Among the acetyltransferases, the NuA4 complex containing Tip60 or its Saccharomyces cerevisiae ortholog, Esa1, is of particular significance because of its roles in crucial genomic processes including DNA damage repair and transcription. The catalytic subunit Esa1 is essential, as are five non-catalytic NuA4 subunits. We found that of these non-catalytic subunits, only deletion of Enhancer of polycomb (Epl1) can be bypassed by loss of a major deacetylase complex. This is a property shared by Esa1. Non-catalytic complex subunits are often critical for complex assembly, stability, genomic targeting, substrate specificity and regulation. Understanding the essential cellular role of Epl1 has been limited, a limitation now overcome by the discovery of its bypass suppression. Here, we present the first comprehensive in vivo study of Epl1 upon complete cellular loss of Epl1 using the powerful tool of suppression combined with transcriptional and mutational analyses. Our results highlight functional parallels between Epl1 and Esa1 and further illustrate that the structural role of Epl1 is important for promotion of Esa1 activity. This conclusion is strengthened by our dissection of Epl1 domains required in vivo for interaction with specific NuA4 subunits, histone acetylation, and chromatin targeting. These results provide new insights for the conserved, essential nature of Epl1 and its homologs among organisms, such as EPC1/2 in humans, which is frequently altered in cancers.
2017-01-19 | GSE92774 | GEO
Project description:Histone acetylation and deacetylation are among the principal mechanisms by which chromatin is regulated during transcription, DNA silencing, and DNA repair. We analyzed patterns of genetic interactions uncovered during comprehensive genome-wide analyses in yeast to probe how histone acetyltransferase (HAT) and histone deacetylase (HDAC) protein complexes interact. The genetic interaction data unveil an underappreciated role of HDACs in maintaining cellular viability, and led us to show that deacetylation of the histone variant Htz1p at lysine 14 is mediated by Hda1p. Studies of the essential nucleosome acetyltransferase of H4 (NuA4) revealed acetylation-dependent protein stabilization of Yng2p, a potential nonhistone substrate of NuA4 and Rpd3C, and led to a new functional organization model for this critical complex. We also found that DNA double-stranded breaks (DSBs) result in local recruitment of the NuA4 complex, followed by an elaborate NuA4 remodeling process concomitant with Rpd3p recruitment and histone deacetylation. These new characterizations of the HDA and NuA4 complexes demonstrate how systematic analyses of genetic interactions may help illuminate the mechanisms of intricate cellular processes. Keywords: genetic modification The 44 datasets in this Series profiled the genome-wide genetic interactions for query genes encoding either HAT and HDAC catalytic subunits or subunits of the associated protein complexes. Of the 32 query genes, 5 were essential and were tested as temperature-sensitive (ts) alleles at three or more temperatures. (ESA1 was also tested as a hypomorphic allele.) The other query genes were tested as null deletion alleles derived from the Yeast Knockout strain collection.
2008-06-11 | E-GEOD-9771 | biostudies-arrayexpress
Project description:Chromatin regulation by the NuA4 acetyltransferase complex is mediated by essential interactions between Enhancer of Polycomb (Epl1) and Esa1
| PRJNA358582 | ENA
Project description:The transcriptional co-activators Mediator and two histone acetyltransferase (HAT) complexes, NuA4 and SAGA, play global roles in transcriptional activation. Here we explore the relative contributions of these factors to RNA polymerase II association at specific genes and gene classes by rapid nuclear depletion of key complex subunits. We show that the NuA4 HAT Esa1 differentially affects certain groups of genes, whereas the SAGA HAT Gcn5 has a weaker but more uniform effect. Relative dependence on Esa1 and Tra1, a shared component of NuA4 and SAGA, distinguishes two large groups of co-regulated growth-promoting genes. In contrast, we show that the activity of Mediator is particularly important at a separate, small set of highly transcribed TATA box-containing genes. Our analysis indicates that at least three distinct combinations of co-activator deployment are used to generate moderate or high transcription levels, and suggests that each may be associated with distinct forms of regulation.
2018-08-15 | GSE109235 | GEO