title: Identification of glutathione S-transferase as a substrate and glutathione as an inhibitor of in vitro calmodulin-stimulated protein methylation in rat liver cytosol.
abstract: This report describes the isolation of the major calmodulin-stimulated methyl acceptor protein of adult rat liver cytosol. This Mr 29,000 methyl acceptor protein (MeAP29) has been purified to apparent homogeneity using ammonium sulfate precipitation and chromatography on DEAE-cellulose, phosphocellulose, hydroxylapatite and Sephadex G-75. Affinity chromatography on glutathione-Sepharose and assays of enzyme activity indicate that MeAP29 is a member of the glutathione S-transferase family. We further show that glutathione can act as an inhibitor of calmodulin-stimulated in vitro methylation of MeAP29 and that MeAP29 methylation is enhanced in non-dialyzed liver cytosol from rats with lowered glutathione levels.
authors.affiliation: Department of Physiological Chemistry, University of Wisconsin Medical School, Madison 53706.
authors.forename: T L
authors.initials: TL
authors.lastname: Neal
authors.forename: L S
authors.initials: LS
authors.lastname: Wright
authors.forename: F L
authors.initials: FL
authors.lastname: Siegel
mesh_terms: D000818:Animals; D002147:Calmodulin / Q000494:pharmacology*; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D005978:Glutathione / Q000494:pharmacology*; D005982:Glutathione Transferase / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008745:Methylation; D008970:Molecular Weight; D011506:Proteins / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D012016:Reference Values; D012436:S-Adenosylmethionine / Q000378:metabolism
chemical_list: D002147:Calmodulin; C057367:MeAP29 protein, rat; D011506:Proteins; D012436:S-Adenosylmethionine; D005982:Glutathione Transferase; D005978:Glutathione