Regulation of Transcription Factor Yin Yang 1 by SET7/9-mediated Lysine Methylation [ChIP-Seq]. Homo sapiens

Yin Yang 1 (YY1) is a multifunctional transcription factor shown to be critical in a variety of biological processes. Although it has been reported to be regulated by multiple types of post-translational modifications (PTMs), whether YY1 is methylated, which enzyme methylates YY1, and hence the functional significance of YY1 methylation remain completely unknown. Here we reported the first methyltransferase, SET7/9 (KMT7), capable of methylating YY1 in vitro and in vivo at two highly conserved lysine (K) residues, K173 and K411, located in two distinct domains, one in the central glycine-rich region and the other in the very carboxyl-terminus. Functional study revealed that SET7/9-mediated YY1 methylation regulated YY1 DNA-binding activity both in vitro and at specific genomic loci in cultured cells. Consistently, SET7/9-mediated YY1 methylation was shown to involve in YY1-regulated gene transcription and cell proliferation. Our findings revealed a novel regulatory strategy, methylation by lysine methyltransferase, imposed on YY1 protein, and linked YY1 methylation with its biological functions. Overall design: The YY1 ChIP-seq in this study was designed to reveal YY1 genomic binding sites in HeLa cells.