title: Reversal of H3K9me2 by a small-molecule inhibitor for the G9a histone methyltransferase.
abstract: Histone lysine methylation has important roles in the organization of chromatin domains and the regulation of gene expression. To analyze its function and modulate its activity, we screened for specific inhibitors against histone lysine methyltransferases (HMTases) using recombinant G9a as the target enzyme. From a chemical library comprising 125,000 preselected compounds, seven hits were identified. Of those, one inhibitor, BIX-01294 (diazepin-quinazolin-amine derivative), does not compete with the cofactor S-adenosyl-methionine, and selectively impairs the G9a HMTase and the generation of H3K9me2 in vitro. In cellular assays, transient incubation of several cell lines with BIX-01294 lowers bulk H3K9me2 levels that are restored upon removal of the inhibitor. Importantly, chromatin immunoprecipitation at several G9a target genes demonstrates reversible reduction of promoter-proximal H3K9me2 in inhibitor-treated mouse ES cells and fibroblasts. Our data identify a biologically active HMTase inhibitor that allows for the transient modulation of H3K9me2 marks in mammalian chromatin.
authors.affiliation: Research Institute of Molecular Pathology, Vienna Biocenter, Dr Bohrgasse 7, A-1030 Vienna, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Kubicek
authors.forename: Roderick J
authors.initials: RJ
authors.lastname: O'Sullivan
authors.forename: E Michael
authors.initials: EM
authors.lastname: August
authors.forename: Eugene R
authors.initials: ER
authors.lastname: Hickey
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.forename: Miguel L
authors.initials: ML
authors.lastname: Teodoro
authors.forename: Stephen
authors.initials: S
authors.lastname: Rea
authors.forename: Karl
authors.initials: K
authors.lastname: Mechtler
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Kowalski
authors.forename: Carol Ann
authors.initials: CA
authors.lastname: Homon
authors.forename: Terence A
authors.initials: TA
authors.lastname: Kelly
authors.forename: Thomas
authors.initials: T
authors.lastname: Jenuwein
mesh_terms: D000818:Animals; D001381:Azepines / Q000494:pharmacology*; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase / Q000037:antagonists & inhibitors* / Q000378:metabolism / Q000502:physiology; D006657:Histones / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D008239:Lysine / Q000737:chemistry / Q000378:metabolism; D008745:Methylation; D051379:Mice; D011401:Promoter Regions, Genetic; D011496:Protein Methyltransferases; D011799:Quinazolines / Q000494:pharmacology*
chemical_list: D001381:Azepines; C518299:BIX 01294; D004791:Enzyme Inhibitors; D006657:Histones; D011799:Quinazolines; D000076983:Histone Methyltransferases; D011496:Protein Methyltransferases; D011495:Histone-Lysine N-Methyltransferase; D008239:Lysine