Project description:By using of paired-end sequencing technology, we report the high-throughput profiling of Jhd2 targeting in S. cerevisiae. We obtained more than 1.8E+7 Illumina reads and generated 1.1E+7 mapped reads from Jhd2-ChIP DNA . Sequence reads for Jhd2-ChIP and Input DNA were mapped to yeast genome by using the BWA (Burrows Wheeler Aligner), SAMtools (Sequence Alignment Map) programs and followed by SICER (Spatial clustering for Identification of ChIP-Enriched Regions) program to obtain the Significant peaks. We found that the overall Jhd2 distribution across the gene body of targets is fairly correlated to the levels of H3K4 di- and tri-methylation, which are enriched at 5’ through 3’ of ORF regions. These observations demonstrate that the Jhd2, a histone H3K4 demethylase, is linked to gene transcription by locating mainly at the coding regions to balance the H3K4me of its target genes at steady state. Furthermore, we observed that Jhd2 are significantly enriched at several specific chromosomal loci including telomeres, centromeres, silent HM loci, LTR-tRNAs, and rDNA arrays. Our study demonstrated that Jhd2, H3K4-demethylase, plays a dynamic role as a chromatin insulator to define boundary regions between euchromatin and heterochromatin by association with specific chromatin loci in the yeast genome.
Project description:project abstract : H3K4 methylation is a well-conserved histone modification from yeast to human. Because H3K4 methylase Set1 and its complex, COMPASS (Complex of proteins associated with Set1), are conserved from yeast to humans, budding yeast has been studied as an acceptable model organism. Since COMPASS components affect Set1 protein stability and H3K4 methylation activity variously, it is important to study how Set1 is regulated by complex components. However, deletion mutant of Swd2 component of COMPASS is not viable, although overexpression of Sen1 fragment enables the construction of Swd2 deletion mutant. This study found that positioning epitope tag to the N-terminal of Swd2 did not decrease interaction between Swd2 and Set1, but reduced the stability of both proteins, Swd2 and Set1, and global H3K4 methylation. Also, we observed that overexpression of N-terminal tagged Swd2 caused increased Set1 protein level and bulk H3K4 methylation. Therefore, Set1 protein can maintain its protein level only when enough Swd2 exist to cover the protein amount of Set1. Also, by comparing RNA sequencing analysis of N-terminal tagged Swd2 and Swd2 deletion mutant with Sen1 fragment overexpression, we isolated genes regulated by Swd2. In conclusion, we suggest that the abundance of Swd2 is important to regulate the protein stability of Set1 and the regulation of gene expression.