Myristylation of gag-onc fusion proteins in mammalian transforming retroviruses.
Four cell lines producing transforming proteins encoded by three mammalian oncogenes (fes, abl, and ras) were investigated for incorporation of [3H]myristate into gag-onc fusion proteins. Using 5-min pulse-labelings, fusion proteins of Abelson murine leukemia virus, Gardner-Arnstein strain of feline sarcoma virus (FeSV), and Snyder-Theilen strain of FeSV were shown to be myristylated. In a 4-hr pulse, p29gag-ras of rat sarcoma virus (RaSV) was also shown to incorporate radiolabel. The fatty acid was recovered from this labeled protein by acid hydrolysis, and identified by reverse-phase thin-layer chromatography to be [3H]myristic acid. The results indicate that substitution of viral gag sequences by cellular oncogene sequences does not abolish their ability to become post-translationally modified by this long chain fatty acid (A. Schultz and S. Oroszlan, J. Virol. 46, 355-361). It is assumed that in the fusion proteins the myristyl moiety is linked through an amide linkage to the amino-terminal glycine as previously found for several retroviral gag precursor polyproteins (L. E. Henderson, H. C. Krutzsch, and S. Oroszlan, Proc. Natl. Acad. Sci. USA 80, 339-343). The possible role of myristylation of transforming proteins is discussed.
D000595:Amino Acid Sequence; D000818:Animals; D000956:Antigens, Viral / Q000235:genetics*; D002471:Cell Transformation, Neoplastic; D015683:Gene Products, gag; D005814:Genes, Viral; D019814:Myristic Acid; D009227:Myristic Acids / Q000378:metabolism*; D009857:Oncogenes; D012190:Retroviridae / Q000235:genetics*; D013045:Species Specificity; D014316:Tritium; D014764:Viral Proteins / Q000235:genetics*
D000956:Antigens, Viral; D015683:Gene Products, gag; D009227:Myristic Acids; D014764:Viral Proteins; D019814:Myristic Acid; D014316:Tritium