Identification of Tup1 and Cyc8 mutations defective in the responses to osmotic stress

Kobayashi, Yoshifumi; Inai, Tomomi; Mizunuma, Masaki; Okada, Ichitaro; Shitamukai, Atsunori; Hirata, Dai; Miyakawa, Tokichi

doi:10.1016/j.bbrc.2008.01.033

Cited by 14 publications

(13 citation statements)

References 14 publications

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“…It is also possible that Gcn5-Hda1 physical interactions are transient and promoter specific, therefore may not be detectable using the methods applied here. Nonetheless, support for our model was provided by reports describing recruitment of Gcn5 to promoters by the Tup1/Ssn6 complex under osmotic stress conditions [40,74], indicating that Tup1/Ssn6 may be a transcriptional activator under certain conditions.…”

Section: Discussionsupporting

confidence: 67%

“…It was previously reported that in cells expressing defective TUP1 , increased Gcn5 was observed at Tup1-repressible promoters, thereby derepressing transcription [40]. We have speculated that the APC may target Gcn5 for turnover in order to progress through the G1/S transition [57].…”

Section: Resultsmentioning

confidence: 99%

“…Acetylation microarrays have shown that Rpd3 and Hda1 are the principal HDACs in yeast, affecting numerous promoters throughout the genome with little overlap between promoters [10,35]. Hda1, an evolutionary conserved HDAC, which deacetylates mainly histones H2B and H3 [36,37], is recruited to promoters via utilization of different Tup1/Ssn6 domains [38-40], resulting in local deacetylation. HDAC recruitment may form a positive feedback loop to repress transcription locally and facilitate the spreading of Tup1 into adjacent regions [41].…”

Section: Introductionmentioning

confidence: 99%

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Antagonistic Gcn5-Hda1 interactions revealed by mutations to the Anaphase Promoting Complex in yeast

et al. 2011

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BackgroundHistone post-translational modifications are critical for gene expression and cell viability. A broad spectrum of histone lysine residues have been identified in yeast that are targeted by a variety of modifying enzymes. However, the regulation and interaction of these enzymes remains relatively uncharacterized. Previously we demonstrated that deletion of either the histone acetyltransferase (HAT) GCN5 or the histone deacetylase (HDAC) HDA1 exacerbated the temperature sensitive (ts) mutant phenotype of the Anaphase Promoting Complex (APC) apc5CA allele. Here, the apc5CA mutant background is used to study a previously uncharacterized functional antagonistic genetic interaction between Gcn5 and Hda1 that is not detected in APC5 cells.ResultsUsing Northerns, Westerns, reverse transcriptase PCR (rtPCR), chromatin immunoprecipitation (ChIP), and mutant phenotype suppression analysis, we observed that Hda1 and Gcn5 appear to compete for recruitment to promoters. We observed that the presence of Hda1 can partially occlude the binding of Gcn5 to the same promoter. Occlusion of Gcn5 recruitment to these promoters involved Hda1 and Tup1. Using sequential ChIP we show that Hda1 and Tup1 likely form complexes at these promoters, and that complex formation can be increased by deleting GCN5.ConclusionsOur data suggests large Gcn5 and Hda1 containing complexes may compete for space on promoters that utilize the Ssn6/Tup1 repressor complex. We predict that in apc5CA cells the accumulation of an APC target may compensate for the loss of both GCN5 and HDA1.

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Section: Discussionsupporting

confidence: 67%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Antagonistic Gcn5-Hda1 interactions revealed by mutations to the Anaphase Promoting Complex in yeast

et al. 2011

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“…The Tup1-Ssn6 complex is involved in the repression of some genes regulated by glucose, oxygen radicals, DNA damage, and other cellular stresses (24–28). Repression via this complex is controlled by a variety of DNA-binding proteins, such as transcriptional regulators, histones, histone deacetylase, and the components of RNA polymerase II holoenzyme (29–33).…”

Section: Introductionmentioning

confidence: 99%

The LAMMER Kinase Homolog, Lkh1, Regulates Tup Transcriptional Repressors through Phosphorylation in Schizosaccharomyces pombe

Kang

Park

2010

Journal of Biological Chemistry

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Disruption of the fission yeast LAMMER kinase, Lkh1, gene resulted in diverse phenotypes, including adhesive filamentous growth and oxidative stress sensitivity, but an exact cellular function had not been assigned to Lkh1. Through an in vitro pull-down approach, a transcriptional repressor, Tup12, was identified as an Lkh1 binding partner. Interactions between Lkh1 and Tup11 or Tup12 were confirmed by in vitro and in vivo binding assays. Tup proteins were phosphorylated by Lkh1 in a LAMMER motif-dependent manner. The LAMMER motif was also necessary for substrate recognition in vitro and cellular function in vivo. Transcriptional activity assays using promoters negatively regulated by Tup11 and Tup12 showed 6 or 2 times higher activity in the Δlkh1 mutant than the wild type, respectively. Northern analysis revealed derepressed expression of the fbp1+ mRNA in Δlkh1 and in Δtup11Δtup12 mutant cells under repressed conditions. Δlkh1 and Δtup11Δtup12 mutant cells showed flocculation, which was reversed by co-expression of Tup11 and -12 with Ssn6. Here, we presented a new aspect of the LAMMER kinase by demonstrating that the activities of global transcriptional repressors, Tup11 and Tup12, were positively regulated by Lkh1-mediated phosphorylation.

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“…These interactions with DNA-binding repressors are mediated mainly through different surfaces of Cyc8, although Tup1 also plays a role in some cases (Komachi et al 1994;Tzamarias and Struhl 1995;Kobayashi et al 2008). Tup1 contains a repression domain that is believed to confer the repressive function of the Cyc8-Tup1 complex via proteinprotein interactions (Tzamarias and Struhl 1994;Green and Johnson 2005).…”

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confidence: 99%

The Cyc8–Tup1 complex inhibits transcription primarily by masking the activation domain of the recruiting protein

Wong¹,

Struhl²

2011

Genes Dev.

125

144

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The yeast Tup1-Cyc8 corepressor complex is recruited to promoters by DNA-binding repressors, but the mechanisms by which it inhibits expression of genes involved in various stress pathways are poorly understood. Conditional and rapid depletion of Tup1 from the nucleus leads to concurrent nucleosome depletion and histone acetylation, recruitment of coactivators (Swi/Snf, SAGA, and Mediator), and increased transcriptional activity. Conversely, coactivator dissociation occurs rapidly upon rerepression by Cyc8-Tup1, although coactivator association and transcription can be blocked even in the absence of nucleosomes. The coactivators are recruited to the sites where Tup1 was located prior to depletion, indicating that the repressor proteins that recruit Tup1 function as activators in its absence. Last, Cyc8-Tup1 can interact with activation domains in vivo. Thus, Cyc8-Tup1 regulates transcription primarily by masking and inhibiting the transcriptional activation domains of the recruiting proteins, not by acting as a corepressor. We suggest that the corepressor function of Cyc8-Tup1 makes only a modest contribution to expression of target genes, specifically to keep expression levels below the nonactivated state.

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Identification of Tup1 and Cyc8 mutations defective in the responses to osmotic stress

Cited by 14 publications

References 14 publications

Antagonistic Gcn5-Hda1 interactions revealed by mutations to the Anaphase Promoting Complex in yeast

Antagonistic Gcn5-Hda1 interactions revealed by mutations to the Anaphase Promoting Complex in yeast

The LAMMER Kinase Homolog, Lkh1, Regulates Tup Transcriptional Repressors through Phosphorylation in Schizosaccharomyces pombe

The Cyc8–Tup1 complex inhibits transcription primarily by masking the activation domain of the recruiting protein

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