The Paf1 complex promotes displacement of histones upon rapid induction of transcription by RNA polymerase II

Heather A Marton,Stephen Desiderio

doi:10.1186/1471-2199-9-4

Heather A Marton, Stephen Desiderio

Open Access

https://doi.org/10.1186/1471-2199-9-4

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Abstract

BackgroundThe yeast Paf1 protein complex is required for efficient transcription elongation by RNA polymerase II (RNA pol II), but the precise role of the complex has been unclear.ResultsHere we show that depletion of the Ctr9 or Paf1 component of the Paf1 complex delays the loss of histones from the GAL1 gene upon induction. This delay in histone removal is accompanied by a decrease in association of RNA pol II with GAL1 and altered distribution of the polymerase along the locus.ConclusionThese observations may explain why initial induction of GAL transcripts is reduced in Ctr9- or Paf1-deficient cells, and is consistent with a model suggesting that the Paf1 complex and the histone modifications that it mediates increase efficiency of transcriptional elongation by promoting nucleosomal destabilization and histone removal.

Highlights

The yeast Paf1 protein complex is required for efficient transcription elongation by RNA polymerase II (RNA pol II), but the precise role of the complex has been unclear
Paf1 and Rtf1 promote the recruitment of Set1 and Set2, a histone H3 K36 methyltransferase, to RNA pol II at sites of active transcription [22,23]. In this communication we show that depletion of the Ctr9 or Paf1 component of the Paf1 complex is associated with delayed loss of histones from the GAL1 gene upon induction, decreased association of RNA pol II with GAL1 and altered distribution of the polymerase along the GAL1 locus
These findings suggest that the occupancy of a locus by the Paf1 complex is positively correlated with its occupancy by RNA pol II

Summary

Introduction

The yeast Paf protein complex is required for efficient transcription elongation by RNA polymerase II (RNA pol II), but the precise role of the complex has been unclear. Several classes of chromatin modifying proteins have been identified; these contribute to gene activation by promoting chromatin decondensation, thereby allowing access of RNA pol II to regulatory sequences and facilitating movement of RNA pol II and associated factors through transcription units. Histone acetyltransferases (GNAT and MYST families) promote chromatin opening, nucleosome fluidity and protein interactions by acetylating histones at specific lysine residues [2]. Efficient transcriptional elongation through chromatin requires additional factors, including FACT, Spt and Asf, which are required for histone eviction and histone redeposition [4,5,6,7]. FACT and Asf may facilitate elongation by stimulating the eviction of H2A/H2B or H3/H4 dimers, respectively, from chromatin

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