Histone chaperone Chz1 facilitates the disfavoring property of Spt16 to H2A.Z-containing genes in Saccharomyces cerevisiae

In this study, we determined the genomic binding profiling of both Htz1 and Pol II and Spt16 using chromatin immunoprecipitation (ChIP)–microarray experiments and sequenced nucleosomal DNA using the next generation sequencing technique in wild-type and chz1 deletion strains of Saccharomyces cerevisiae. The results revealed that Spt16 and RNA polymerase II are associated, bind at nucleosome-depleted regions, and are positively correlated with transcription rate. Importantly, Spt16 disfavors the Htz1-bound genes, and this discrimination is impaired upon deletion of chz1. The anti-correlation between binding profiles of Spt16 and Htz1 at promoters is not an intrinsic repellence, but is probably due to a requirement for transcription initiation. We showed that chz1 deletion decreases Htz1 binding at promoters and telomeres. Also, in the chz1 deletion mutant, Spt16 binding at ribosomal genes was lost. We inferred the discrimination of Spt16 to Htz1-bound genes is due to priority of Chz1 to Spt16 in binding to Htz1-bound genomic regions; Chz1-escorted Htz1 further limits binding of Spt16 to it. Our analysis suggested that Chz1-delivered Htz1 impairs Spt16 binding at chromatin.

Source: BJ Gene - April 8, 2014 Category: Biochemistry Authors: H Liu, Z Zhou, K Luo, Y Mu, Y Wan Tags: BJ Gene Source Type: research