Phosphorylation of the PRC2 component Ezh2 is cell cycle-regulated and up-regulates its binding to ncRNA

Syuzo Kaneko; Gang Li; Jinsook Son; Chong-Feng Xu; Raphael Margueron; Thomas A. Neubert; Danny Reinberg

doi:10.1101/gad.1983810

Phosphorylation of the PRC2 component Ezh2 is cell cycle-regulated and up-regulates its binding to ncRNA

¹Howard Hughes Medical Institute, New York University School of Medicine, New York, New York 10016, USA;
²Department of Biochemistry, New York University School of Medicine, New York, New York 10016, USA;
³Department of Pharmacology, Kimmel Center for Biology and Medicine, Skirball Institute, New York University School of Medicine, New York, New York 10016, USA

↵5 Present address: Research Center Unité de Génétique et Biologie du Développement, Curie Institute, 75248 Paris Cedex 05, France.

↵4 These authors contributed equally to this work.

Abstract

Ezh2 functions as a histone H3 Lys 27 (H3K27) methyltransferase when comprising the Polycomb-Repressive Complex 2 (PRC2). Trimethylation of H3K27 (H3K27me3) correlates with transcriptionally repressed chromatin. The means by which PRC2 targets specific chromatin regions is currently unclear, but noncoding RNAs (ncRNAs) have been shown to interact with PRC2 and may facilitate its recruitment to some target genes. Here we show that Ezh2 interacts with HOTAIR and Xist. Ezh2 is phosphorylated by cyclin-dependent kinase 1 (CDK1) at threonine residues 345 and 487 in a cell cycle-dependent manner. A phospho-mimic at residue 345 increased HOTAIR ncRNA binding to Ezh2, while the phospho-mimic at residue 487 was ineffectual. An Ezh2 domain comprising T345 was found to be important for binding to HOTAIR and the 5′ end of Xist.