title: Methionine adenosyltransferase II serves as a transcriptional corepressor of Maf oncoprotein.
abstract: Protein methylation pathways comprise methionine adenosyltransferase (MAT), which produces S-adenosylmethionine (SAM) and SAM-dependent substrate-specific methyltransferases. However, the function of MAT in the nucleus is largely unknown. MafK represses or activates expression of heme oxygenase-1 (HO-1) gene, depending on its heterodimer partners. Proteomics analysis of MafK revealed its interaction with MATIIα, a MAT isozyme. MATIIα was localized in nuclei and found to form a dense network with chromatin-related proteins including Swi/Snf and NuRD complexes. MATIIα was recruited to Maf recognition element (MARE) at HO-1 gene. When MATIIα was knocked down in murine hepatoma cell line, expression of HO-1 was derepressed at both basal and induced levels. The catalytic activity of MATIIα, as well as its interacting factors such as MATIIβ, BAF53a, CHD4, and PARP1, was required for HO-1 repression. MATII serves as a transcriptional corepressor of MafK by interacting with chromatin regulators and supplying SAM for methyltransferases.
authors.affiliation: Department of Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Miyagi 980-8575, Japan.
authors.forename: Yasutake
authors.initials: Y
authors.lastname: Katoh
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Ikura
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Hoshikawa
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tashiro
authors.forename: Takashi
authors.initials: T
authors.lastname: Ito
authors.forename: Mineto
authors.initials: M
authors.lastname: Ohta
authors.forename: Yohei
authors.initials: Y
authors.lastname: Kera
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Noda
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Igarashi
mesh_terms: D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000378:metabolism; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic; D051547:Heme Oxygenase-1 / Q000096:biosynthesis; D006657:Histones / Q000378:metabolism; D006801:Humans; D007527:Isoenzymes / Q000737:chemistry; D008113:Liver Neoplasms / Q000378:metabolism; D008716:Methionine Adenosyltransferase / Q000378:metabolism*; D051379:Mice; D015513:Oncogene Proteins / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D051257:Proto-Oncogene Proteins c-maf / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D006657:Histones; D007527:Isoenzymes; C495607:MAF protein, human; C495608:Maf protein, mouse; D015513:Oncogene Proteins; D051257:Proto-Oncogene Proteins c-maf; D051547:Heme Oxygenase-1; C527161:MAT2A protein, human; D008716:Methionine Adenosyltransferase