Project description:We found ribosomal transcription factor Ifh1p is dynamically acetylated and phosphorylated in response to nutrient cues. ChIP-seq data revealed dynamic binding to ribosomal genes (RP) during the OX growth phase of the yeast metabolic cycle (YMC) when RP genes are highly induced, and weaker binding in the RC quiescent-like phase. Besides RP genes, our ChIP-seq data also reveals binding of Ifh1p to non-RP genes such as translation factors and metabolic genes. Examination of Ifh1p binding over two timepoints of the YMC (OX, RC) using Input as the control.
Project description:We found ribosomal transcription factor Ifh1p is dynamically acetylated and phosphorylated in response to nutrient cues. ChIP-seq data revealed dynamic binding to ribosomal genes (RP) during the OX growth phase of the yeast metabolic cycle (YMC) when RP genes are highly induced, and weaker binding in the RC quiescent-like phase. Besides RP genes, our ChIP-seq data also reveals binding of Ifh1p to non-RP genes such as translation factors and metabolic genes.
Project description:We found acetyl-CoA levels increase when cells are committed to growth. We also found 3 components of the SAGA complex, Spt7p, Sgf73p and Ada3p as well as histones are dynamically acetylated in tune with the acetyl-CoA levels. ChIP-seq study reveals SAGA and H3K9ac predominantly occupy growth genes at the OX growth phase of the yeast metabolic cycle indicating acetyl-CoA levels may drive growth gene transcription program through acetylation of these proteins.
Project description:We found acetyl-CoA levels increase when cells are committed to growth. We also found 3 components of the SAGA complex, Spt7p, Sgf73p and Ada3p as well as histones are dynamically acetylated in tune with the acetyl-CoA levels. ChIP-seq study reveals SAGA and H3K9ac predominantly occupy growth genes at the OX growth phase of the yeast metabolic cycle indicating acetyl-CoA levels may drive growth gene transcription program through acetylation of these proteins. Examination of H3K9ac and SAGA binding over two timepoints using H3 and Input as controls
Project description:Quiescence is a distinct cell cycle phase, termed G0, in which growth, transcription, translation, and replication are suppressed. Yeast cells enter G0 following glucose exhaustion but remain viable for an extended period and can re-enter the cell cycle when returned to glucose-rich medium. Quiescence is a feature of all organisms and is essential for the maintenance of stem cells and tissue renewal. Quiescence is also related to chronological lifespan (CLS) - or the capacity of post-mitotic quiescent cells to survive over time - and thus contributes to longevity. However, important questions remain to be answered regarding the mechanisms that control entry into quiescence, the maintenance of quiescence, and the re-entry of quiescent cells into the cell cycle. Histone acetylation is lost during the formation of quiescent yeast cells, and chromatin becomes highly condensed. This unique chromatin landscape plays a key role in supporting quiescence-specific transcriptional repression and has been linked to the formation and maintenance of quiescent cells. To ask if other chromatin features regulate quiescence, we conducted a comprehensive screen of histone H3 and H4 mutants. We identified several mutants that show altered quiescence entry and have characterized their chromatin phenotypes. None of these mutants retain histone acetylation, while several have altered chromatin condensation. Additionally, a screen for H3 and H4 mutants with altered chronological lifespan showed that CLS is highly correlated with quiescence entry.
