title: Guanine nucleotide-dependent carboxyl methylation of mammalian membrane proteins.
abstract: A guanine nucleotide-dependent protein carboxyl methylation is demonstrated in mammalian cell membranes. The methylation of membrane proteins of Mr 20,000-23,000 requires S-adenosylmethionine, GTP or nonhydrolyzable GTP analogs, and a cytoplasmic methyltransferase. The protein methyl groups are stable at neutral pH and under basic conditions hydrolyze to produce methanol. The specific methyl acceptor proteins and methyltransferases varied between tissues and cell types, suggesting that these methylations have cell-specific functions. The guanine nucleotide-dependent carboxyl methylations provide a possible mechanism for regulating the function of GTP-binding membrane proteins in the transduction of receptor-mediated signals of eukaryotic cells.
authors.affiliation: Laboratory of General and Comparative Biochemistry, National Institute of Mental Health, Bethesda, Maryland 20892.
authors.forename: P S
authors.initials: PS
authors.lastname: Backlund
authors.forename: R R
authors.initials: RR
authors.lastname: Aksamit
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D002460:Cell Line; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D008565:Membrane Proteins / Q000302:isolation & purification / Q000378:metabolism*; D008745:Methylation; D008970:Molecular Weight; D011496:Protein Methyltransferases / Q000378:metabolism; D012436:S-Adenosylmethionine / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; D012436:S-Adenosylmethionine; D006160:Guanosine Triphosphate; D011496:Protein Methyltransferases