Project description:The changes in gene expression can be epigenetically regulated by histone modifications. As PKCB is known to phosphorylate H3T6 leading to gene activation, we examined if the changes in gene expression seen in B cell activation were associated with H3T6 phosphorylation. We want to examine how PKCB mutation will affect H3T6 phosphorylation on a genome-wide level and so we performed ChIP-seq with H3T6 phosphorylation in wildtype and C57BL/6 Tilcara (Til) mouse, a PKCβ mutant mice model.
Project description:R-loops are transcription by-products that may constitute a threat to genome integrity.We previously show in Saccharomyces cerevisiae that R-loops are tightly and specifically linked with histone H3-Ser10 phosphorylation (H3S10P), a mark of chromatin condensation. Here we analyse the hpr1-101 mutant. A point mutation that impairs transcription and mRNP biogenesis without increasing recombination. Importantly, ChIP-chip analyses reveal a clear H3S10P does not accumulate at the pericentromeric chromatin during the G1-phase of the cell cycle but during S-phase in non-accumulating R-loop hpr1-101. ChIP-chip studies were perfomed with antibodies against Histone H3 and the phosphorylated Histone H3 at Serine10 in the yeast S. cerevisiae.
Project description:The re-assembly of chromatin following DNA replication is a critical event in the maintenance of genome integrity. Histone H3 acetylation at K56 and phosphorylation at T45 are two important chromatin modifications that accompany chromatin assembly. Here we report a microarray expression study of the protein kinase Pkc1, histone acetyl transferase Rtt109 and histone H3 in Saccharomyces cerevisiae under conditions of replicative stress.
Project description:Pkm1 and Pkm2 kinases are expressed in differentiating skeletal myoblasts. Knockdown of Pkm1 or Pkm2, therefore, can affect myoblast differentiation, by two independent regulatory mechanisms involving histone phosphorylation and chromatin remodeling complexes. Pkm2 KD in C2C12 cells reduced the chromatin marks of phosphorylated H3-T6, H3-T11 and H3-T45 into several essential myogenic promoters, and consequently, prevented their expression. Also, the transcriptional analysis demonstrated that Pkm2 is required for the expression of the cBAF-specific subunits Dpf2 and Baf250a, which we have previously demonstrated are essential for myogenesis. In contrast, Pkm1 KD alters the localization of nuclear Dpf2 into the cytoplasm as well. Mechanistically, Pkm KD resulted in decreased binding of cBAF components to their myogenic target genes, which also suggested a positive regulation between the cBaf complex and the H3 phosphorylation marks.
Project description:R-loops are transcription by-products that may constitute a threat to genome integrity. In addition to specific enzymes to remove them, eukaryotes rely on a number of mRNP biogenesis factors such as the THO complex, to prevent co-transcriptional R-loop formation. We show in Saccharomyces cerevisiae that R-loops are tightly and specifically linked with histone H3-Ser10 phosphorylation (H3S10P), a mark of chromatin condensation. Importantly, ChIP-chip analyses reveal a clear H3S10P accumulation at the pericentromeric chromatin during the G1-phase of the cell cycle only in R loop-accumulating yeast strains but not in those non-accumulating R-loops, and a significantly higher accumulation during S-phase. Such a difference can also be detected in a number of genes along the genome. ChIP-chip studies were perfomed with antibodies against Histone H3 and the phosphorylated Histone H3 at Serine10 in the yeast S. cerevisiae.
Project description:We used ChIP-seq to determine the whole-genome enrichment of histone H3 threonine 11 phosphorylation (H3 T11ph) during Saccharomyces cerevisiae meiosis. S. cerevisiae SK1 cells were synchronized for meiotic entry and 3 and 4 hour meiotic samples were obtained. As H3 T11ph is dependent on the formation of meiotic double strand breaks (DSBs), a negative control ChIP-seq sample was obtained from a strain lacking DSBs (spo11-yf). Concurrently, ChIP-seq was carried out for histone H3 as a control for comparision.
Project description:The following CGH experiments were conducted on four sectors (S1-S4) from a single primary ductal carcinoma tumor (T6) using the Sector-Ploidy-Profiling (SPP) Approach. SPP involves macro-dissecting the tumor, flow-sorting nuclei by differences in total genomic DNA content and profiling the genome of the tumor subpopulations.
Project description:Saccharomyces cerevisiae Mek1 is a CHK2/Rad53-family kinase that regulates meiotic recombination and progression upon its activation in response to DNA double-strand breaks (DSBs). The full catalog of direct Mek1 phosphorylation targets remains unknown. Here, we show that phosphorylation of histone H3 on threonine 11 (H3 T11ph) is induced by meiotic DSBs in S. cerevisiae and Schizosaccharomyces pombe. Molecular genetic experiments in S. cerevisiae confirmed that Mek1 is required for H3 T11ph and revealed that phosphorylation is rapidly reversed when Mek1 kinase is no longer active. Reconstituting histone phosphorylation in vitro with recombinant proteins demonstrated that Mek1 directly catalyzes H3 T11 phosphorylation. Mutating H3 T11 to nonphosphorylatable residues conferred no detectable meiotic defects, indicating that H3 T11ph is dispensable for Mek1 functions in controlling recombination. However, H3 T11ph provides an excellent marker of ongoing Mek1 kinase activity in vivo. Anti-H3 T11ph chromatin immunoprecipitation followed by deep sequencing demonstrated that H3 T11ph was highly enriched at presumed sites of attachment of chromatin to chromosome axes, gave a more modest signal along chromatin loops, and was present at still lower levels immediately adjacent to DSB hotspots. These localization patterns closely tracked the distribution of Red1 and Hop1, axis proteins required for Mek1 activation. These findings provide insight into the spatial disposition of Mek1 kinase activity and the higher order organization of recombining meiotic chromosomes.