Open AccessTranscription Regulation by the Noncoding RNA SRG1 Requires Spt2-Dependent Chromatin Deposition in the Wake of RNA Polymerase II
Author(s) -
Philippe Thebault,
Geneviève Boutin,
Wajid Waheed Bhat,
Anne Rufiange,
Joseph A. Martens,
Amine Nourani
Publication year - 2011
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.01083-10
Subject(s) - biology , rna polymerase ii , chromatin , transcription (linguistics) , nucleosome , microbiology and biotechnology , rna polymerase , rna , general transcription factor , non coding rna , promoter , genetics , gene , gene expression , linguistics , philosophy
Spt2 is a chromatin component with roles in transcription and posttranscriptional regulation. Recently, we found that Spt2 travels with RNA polymerase II (RNAP II), is involved in elongation, and plays important roles in chromatin modulations associated with this process. In this work, we dissect the function of Spt2 in the repression ofSER3 . This gene is repressed by a transcription interference mechanism involving the transcription of an adjacent intergenic region,SRG1 , that leads to the production of a noncoding RNA (ncRNA). We find that Spt2 and Spt6 are required for the repression ofSER3 bySRG1 transcription. Intriguingly, we demonstrate that these effects are not mediated through modulations of theSRG1 transcription rate. Instead, we show that theSRG1 region overlapping theSER3 promoter is occluded by randomly positioned nucleosomes that are deposited behind RNAP II transcribingSRG1 and that their deposition is dependent on the presence of Spt2. Our data indicate that Spt2 is required for the major chromatin deposition pathway that uses old histones to refold nucleosomes in the wake of RNAP II at theSRG1 -SER3 locus. Altogether, these observations suggest a new mechanism of repression by ncRNA transcription involving a repressive nucleosomal structure produced by an Spt2-dependent pathway following RNAP II passage.