Document Type

Article

Publication Date

8-1-2014

Publication Title

Nucleic acids research

ISSN

1362-4962

Volume

42

Issue

14

First Page

9236

Last Page

9248

DOI

https://doi.org/10.1093/nar/gku540

Abstract

Polycomb repressive complex-2 (PRC2) is a histone methyltransferase required for epigenetic silencing during development and cancer. Long non-coding RNAs (lncRNAs) can recruit PRC2 to chromatin. Previous studies identified PRC2 subunits in a complex with the apparent molecular weight of a dimer, which might be accounted for by the incorporation of additional protein subunits or RNA rather than PRC2 dimerization. Here we show that reconstituted human PRC2 is in fact a dimer, using multiple independent approaches including analytical size exclusion chromatography (SEC), SEC combined with multi-angle light scattering and co-immunoprecipitation of differentially tagged subunits. Even though it contains at least two RNA-binding subunits, each PRC2 dimer binds only one RNA molecule. Yet, multiple PRC2 dimers bind a single RNA molecule cooperatively. These observations suggest a model in which the first RNA binding event promotes the recruitment of multiple PRC2 complexes to chromatin, thereby nucleating repression.

Comments

Publication of this article was funded by the University of Colorado Boulder Libraries Open Access Fund.

This article was originally published in Nucleic Acids Research.

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