Project description:Acetylation and dimethylation of lysine 9 on histone H3 are prominent marks of euchromatin and heterochromatin, respectively. Moreover, histone acetylation has been linked to lipid metabolism. We have previously identified the transcription factor Cbf11 as a regulator of lipid metabolism and genome integrity in the fission yeast. Cut6, the acetyl-CoA carboxylase, is one of direct targets of Cbf11. To link the role of Cbf11 in lipid metabolism and chromatin regulation we have performed ChIP-seq of H3K9ac, H3K9me2 and H3 in WT and cbf11KO strains of Schizosaccharomyces pombe in three biological replicates. Strain genotypes: wild type JB32 (h+s); cbf11 knock-out MP44 (h+ cbf11::natR).
Project description:Expression profiles of polg mutant cells reveal that many genes encoding proteins involved in cell wall biogenesis and stress response are induced, suggesting that polg mutant cells attempt to maintain growth potential and undergo extensive oxidative metabolism. Conversely, many genes encoding proteins involved in ribosome biogenesis and respiration are repressed, indicating that cells depleted of mtDNA are adapted to grow slowly in absence of mitochondrial function. Keywords: Schizosaccharomyces pombe ployg mutant cells vs wild type cells.
Project description:Spt6 is a conserved factor, critically required for several transcription and chromatin related processes. We now show that Spt6 and its binding partner, Iws1, are required for heterochromatic silencing in Schizosaccharomyces pombe. Our studies demonstrate that Spt6 is required for silencing of all heterochromatic loci and that an spt6 mutant has an unusual combination of heterochromatic phenotypes compared to previously studied silencing mutants. Unexpectedly, we find normal nucleosome positioning over heterochromatin and normal levels of histone H3K9 dimethylation. However, we also find greatly reduced levels of H3K9 trimethylation, elevated levels of H3K14 acetylation, and reduced recruitment of several silencing factors. Our evidence suggests that Spt6 plays a role at both the transcriptional and post-transcriptional levels; in an spt6 mutant, RNA polymerase II (RNAPII) occupancy at the pericentric regions is only modestly increased, while production of small interfering RNAs (siRNAs) is lost. Taken together, our results suggest that Spt6 is required for multiple steps in heterochromatic silencing by controlling chromatin, transcriptional, and post-transcriptional processes.
