4sU-seq analysis of Xist-mediated chromosomal silencing
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ABSTRACT: The Polycomb repressive complexes PRC1 and PRC2 play a key role in chromosome silencing by Xist RNA. Previously we have shown that initation of Polycomb recruitment is mediated by the PCGF3/5-PRC1 complex, which catalyses chromosome-wide H2A ubiquitylation (H2AK119u1), signalling recruitment of other PRC1 complexes, and PRC2. However, the molecular basis for PCGF3/5-PRC1 recruitment by Xist RNA remains unknown. Here we define the Xist RNA Polycomb Interaction Domain (XR-PID), a 600 nt element encompassing the Xist B-repeat element. XR-PID is required for Polycomb recruitment by Xist RNA, Xist-mediated chromosome silencing. We identify the RNA-binding protein hnRNPK as the principal XR-PID binding factor required to recruit PCGF3/5-PRC1. Accordingly, synthetically tethering hnRNPK to Xist RNA lacking the B-repeat is sufficient for Xist-dependent Polycomb recruitment. Our findings resolve the molecular mechanism for Polycomb recruitment by Xist RNA, providing key insights into chromatin modification by non-coding RNA.
ORGANISM(S): Mus musculus
PROVIDER: GSE99924 | GEO | 2017/12/08
SECONDARY ACCESSION(S): PRJNA390136
REPOSITORIES: GEO
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