title: Myristic acid, a rare fatty acid, is the lipid attached to the transforming protein of Rous sarcoma virus and its cellular homolog.
abstract: The lipid bound to p60src, the transforming protein of Rous sarcoma virus, has been identified by gas and thin-layer chromatography as the 14-carbon saturated fatty acid, myristic acid. The protein can be labeled biosynthetically with either [3H]myristic acid or [3H]palmitic acid. Incorporation of [3H]myristic acid was noticeably greater than incorporation of [3H]palmitic acid. All of the [3H]myristic acid-derived label in p60src was present as myristic acid. In contrast, none of the radioactivity derived from [3H]palmitic acid was recovered as palmitic acid. Instead, all 3H incorporated into p60src from [3H]palmitic acid arose by metabolism to myristic acid. The cellular tyrosine kinase, p60c-src also contains myristic acid. By comparison of the extent of myristylation of p60v-src with that of the Moloney murine leukemia virus structural protein precursor, Pr65gag, we estimate that greater than 80% of the molecules of p60v-src contain one molecule of this fatty acid. Myristylation is a rare form of protein modification. p60v-src contains 10 to 40% of the myristic acid bound to protein in cells transformed by Rous sarcoma virus and is easily identified in total cell lysates when [3H]myristic acid-labeled proteins are separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Comparison of the amount of [3H]myristic acid-labeled p60src in total cell lysates and in immunoprecipitates suggests that immunoprecipitation with rabbit anti-Rous sarcoma virus tumor sera detects ca. 25% of the p60src present in cells.
authors.forename: J E
authors.initials: JE
authors.lastname: Buss
authors.forename: B M
authors.initials: BM
authors.lastname: Sefton
mesh_terms: D000818:Animals; D001358:Avian Sarcoma Viruses / Q000235:genetics*; D002471:Cell Transformation, Neoplastic; D002478:Cells, Cultured; D002642:Chick Embryo; D002849:Chromatography, Gas; D007700:Kinetics; D019814:Myristic Acid; D009227:Myristic Acids / Q000032:analysis* / Q000378:metabolism; D015688:Oncogene Protein pp60(v-src); D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism; D010446:Peptide Fragments / Q000032:analysis; D011494:Protein Kinases / Q000302:isolation & purification*; D013462:Sulfur Radioisotopes; D014316:Tritium; D014764:Viral Proteins / Q000096:biosynthesis / Q000302:isolation & purification*
chemical_list: D009227:Myristic Acids; D010169:Palmitic Acids; D010446:Peptide Fragments; D013462:Sulfur Radioisotopes; D014764:Viral Proteins; D019814:Myristic Acid; D014316:Tritium; D019308:Palmitic Acid; D011494:Protein Kinases; D015688:Oncogene Protein pp60(v-src)