title: RNase treatment of yeast and mammalian cell extracts affects in vitro substrate methylation by type I protein arginine N-methyltransferases.
abstract: Type I protein arginine N-methyltransferases catalyze the formation of omega-NG-monomethylarginine and asymmetric omega-NG, NG-dimethylarginine residues using S-adenosyl-l-methionine as the methyl donor. In vitro these enzymes can modify a number of soluble methyl-accepting substrates in yeast and mammalian cell extracts including several species that interact with RNA. We treated normal and hypomethylated Saccharomyces cerevisiae and RAT1 cell extracts with RNase prior to in vitro methylation by recombinant protein N-arginine methyltransferases and found that the methylation of certain polypeptides is enhanced up to 12-fold whereas that of others is diminished. 2-D gel electrophoresis of RNase-treated yeast extracts allowed us to tentatively identify the glycine- and arginine-rich (GAR) domain-containing proteins Gar1, Nop1, Sbp1, and Npl3 as major methyl-acceptors based on their known isoelectric points and apparent molecular weights. These results suggest that the methylation and RNA-binding of GAR domain-containing proteins in vivo may regulate protein-nucleic acid or protein-protein interactions.
authors.affiliation: Department of Chemistry & Biochemistry and Molecular Biology Institute, UCLA, Los Angeles, California 90095-1569, USA.
authors.forename: A
authors.initials: A
authors.lastname: Frankel
authors.forename: S
authors.initials: S
authors.lastname: Clarke
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000032:analysis; D002460:Cell Line; D029941:Fish Proteins; D005656:Fungal Proteins / Q000032:analysis; D008745:Methylation; D009687:Nuclear Proteins / Q000032:analysis; D010455:Peptides / Q000032:analysis / Q000378:metabolism; D011484:Protein-Arginine N-Methyltransferases / Q000378:metabolism*; D016601:RNA-Binding Proteins; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D012260:Ribonucleases / Q000494:pharmacology*; D020718:Ribonucleoproteins, Small Nucleolar; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D013379:Substrate Specificity
chemical_list: D001798:Blood Proteins; D029941:Fish Proteins; D005656:Fungal Proteins; C064793:NOP1 protein, S cerevisiae; C077734:NPL3 protein, S cerevisiae; D009687:Nuclear Proteins; D010455:Peptides; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D020718:Ribonucleoproteins, Small Nucleolar; C088488:SBP1 protein, Parablax neblifer; D029701:Saccharomyces cerevisiae Proteins; C073180:GAR1 protein, S cerevisiae; D011484:Protein-Arginine N-Methyltransferases; D012260:Ribonucleases