Project description:We report the genome-wide Chd1 co-occupancy with early transcription elongation factors ChIP-seq for Chd1 and elongating RNA polymerase II
Project description:We report genome-wide Chd1 occupancy in WT and in ten elongation factor mutants, and genome-wide H3K4me3/H3K36me3 profiles in WT and CHD1 mutant.
Project description:Chd1 is a conserved ATP-dependent chromatin remodeler that maintains the nucleosomal structure of chromatin, but the determinants of its specificity and its impact on gene expression are not well defined. To identify the determinants of Chd1 binding specificity in the yeast genome, we investigated Chd1 occupancy in mutants of several candidate factors. We found that several components of the PAF1 transcription elongation complex contribute to Chd1 recruitment to highly transcribed genes, and identified Spt4 as a factor that appears to negatively modulate Chd1 binding to chromatin. We discovered that CHD1 loss alters H3K4me3 and H3K36me3 patterns throughout the yeast genome. Interestingly, the aberrant histone H3 methylation patterns were predominantly observed within 1 kb from the transcription start site, where both histone H3 methylation marks co-occur. A reciprocal change between the two marks was obvious in the absence of Chd1, suggesting a role for CHD1 in establishing or maintaining the boundaries of these largely mutually exclusive histone marks. Strikingly, intron-containing genes were most susceptible to CHD1 loss, and exhibited a high degree of histone H3 methylation changes. Intron retention was significantly lower in the absence of CHD1, suggesting that CHD1 function as a chromatin remodeler could indirectly affect RNA splicing. This SuperSeries is composed of the SubSeries listed below.
Project description:Monoubiquitination of histone H2B on lysine 123 (H2BK123ub) is a transient histone modification considered to be essential for establishing H3K4 and H3K79 trimethylation by Set1/COMPASS and Dot1, respectively. Many of the factors such as Rad6/Bre1, the Paf1 complex, and the Bur1/Bur2 complex were identified to be required for proper histone H3K4 and H3K79 trimethylation, and were shown to function by regulating H2BK123ub levels. Here, we have identified Chd1 as a factor that is required for proper maintenance of H2B monoubiquitination levels, but not for H3K4 and H3K79 trimethylation. Loss of Chd1 results in a substantial loss of H2BK123ub levels with little to no effect on the genome-wide pattern of H3K4 and H3K79 trimethylation. Our data shows that nucleosomal occupancy is reduced in gene bodies in both CHD1 null and K123A backgrounds. We have also demonstrated that Chd1’s function in maintaining H2BK123ub levels is conserved from yeast to human. Our study provides evidence that only small levels of H2BK123ub are necessary for full levels of H3K4 and H3K79 trimethylation in vivo, and points to a role for Chd1 in positively regulating gene expression through promoting nucleosome re-assembly coupled with H2B monoubiquitination. Examination of two histone modifications in wild-type and Chd1 null yeast strains using ChIP-seq. Expression profiling in wild-type and Chd1 null yeast strains using RNA-seq.
Project description:Monoubiquitination of histone H2B on lysine 123 (H2BK123ub) is a transient histone modification considered to be essential for establishing H3K4 and H3K79 trimethylation by Set1/COMPASS and Dot1, respectively. Many of the factors such as Rad6/Bre1, the Paf1 complex, and the Bur1/Bur2 complex were identified to be required for proper histone H3K4 and H3K79 trimethylation, and were shown to function by regulating H2BK123ub levels. Here, we have identified Chd1 as a factor that is required for proper maintenance of H2B monoubiquitination levels, but not for H3K4 and H3K79 trimethylation. Loss of Chd1 results in a substantial loss of H2BK123ub levels with little to no effect on the genome-wide pattern of H3K4 and H3K79 trimethylation. Our data shows that nucleosomal occupancy is reduced in gene bodies in both CHD1 null and K123A backgrounds. We have also demonstrated that Chd1’s function in maintaining H2BK123ub levels is conserved from yeast to human. Our study provides evidence that only small levels of H2BK123ub are necessary for full levels of H3K4 and H3K79 trimethylation in vivo, and points to a role for Chd1 in positively regulating gene expression through promoting nucleosome re-assembly coupled with H2B monoubiquitination.