Recruitment of mRNA cleavage/polyadenylation machinery by the yeast chromatin protein Sin1p/Spt2p
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Edited by Roger D. Kornberg, Stanford University School of Medicine, Stanford, CA, and approved May 18, 2006 (received for review March 13, 2006)
Abstract
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.
Footnotes
- †To whom correspondence should be addressed. E-mail: katcoff{at}mail.biu.ac.il
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↵*Present address: Procognia Israel, Ashdod 77610, Israel.
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Author contributions: G.H. and D.J.K. designed research; G.H., H.B., R.C., and D.J.K. performed research; G.H. and D.J.K. analyzed data; and G.H. and D.J.K. wrote the paper.
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Conflict of interest statement: No conflicts declared.
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This paper was submitted directly (Track II) to the PNAS office.
- Abbreviations:
- CTD,
- C-terminal domain.
Abbreviation:
- © 2006 by The National Academy of Sciences of the USA
