Recruitment of mRNA cleavage/polyadenylation machinery by the yeast chromatin protein Sin1p/Spt2p.
The yeast chromatin protein Sin1p/Spt2p has long been studied, but the understanding of its function has remained elusive. The protein has sequence similarity to HMG1, specifically binds crossing DNA structures, and serves as a negative transcriptional regulator of a small family of genes that are activated by the SWI/SNF chromatin-remodeling complex. Recently, it has been implicated in maintaining the integrity of chromatin during transcription elongation. Here we present experiments whose results indicate that Sin1p/Spt2 is required for, and is directly involved in, the efficient recruitment of the mRNA cleavage/polyadenylation complex. This conclusion is based on the following findings: Sin1p/Spt2 frequently binds specifically downstream of many ORFs but almost always upstream of the first polyadenylation site. It directly interacts with Fir1p, a component of the cleavage/polyadenylation complex. Disruption of Sin1p/Spt2p results in foreshortened poly(A) tracts on mRNA. It is synthetically lethal with Cdc73p, which is involved in the recruitment of the complex. This report shows that a chromatin component is involved in 3' end processing of RNA.
Pubmed ID: 16788068 RIS Download
3' Untranslated Regions | Carrier Proteins | Chromatin | Chromosomal Proteins, Non-Histone | DNA-Binding Proteins | Genes, Lethal | Nuclear Proteins | Polyadenylation | RNA, Messenger | Saccharomyces cerevisiae | Saccharomyces cerevisiae Proteins | mRNA Cleavage and Polyadenylation Factors