title: v-mos proteins encoded by myeloproliferative sarcoma virus and its ts159 mutant.
abstract: The myeloproliferative sarcoma virus (MPSV) v-mos protein was predicted to be identical in size to p39c-mos because of an observed one-base deletion in the seventh codon of the env-mos open reading frame, which would allow translation to initiate at the methionine equivalent to codon 32 of the env-mos gene. On the basis of published results, p39c-mos is known to have greatly reduced in vitro protein kinase activity compared with p37env-mos encoded by Moloney murine sarcoma virus. Unexpectedly, the relative activity of the MPSV v-mos protein kinase was comparable to that of p37env-mos. Consistent with this finding, the size of MPSV v-mos protein was found to be similar to the size of p37env-mos. Moreover, the pattern and sizes of phosphorylated bands produced by autophosphorylation of the MPSV v-mos protein were similar to those of p37env-mos. These results were confirmed by in vitro transcription-translation of the MPSV v-mos gene. Resequencing portions of the MPSV mos gene failed to show the deletion within codon 7. Except for the codon 262 deletion, other mutations characteristic of MPSV and temperature-sensitive MPSV v-mos genes were confirmed. A glycine-to-arginine mutation at residue 338 of the MPSV env-mos sequence, previously shown to cause thermosensitivity of the mutant virus (termed ts159) transforming function, yielded a v-mos protein that had significantly reduced protein kinase activity in vitro. These findings indicate that MPSV, like other Moloney murine sarcoma virus strains, also encodes a functional env-mos protein.
authors.affiliation: Department of Molecular Pathology, University of Texas M.D. Anderson Cancer Center, Houston 77030.
authors.forename: B
authors.initials: B
authors.lastname: Singh
authors.forename: C
authors.initials: C
authors.lastname: Stocking
authors.forename: R
authors.initials: R
authors.lastname: Walker
authors.forename: Y D
authors.initials: YD
authors.lastname: Yang
authors.forename: W
authors.initials: W
authors.lastname: Ostertag
authors.forename: R B
authors.initials: RB
authors.lastname: Arlinghaus
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002872:Chromosome Deletion; D004229:Dithiothreitol / Q000494:pharmacology; D015752:Genes, env; D016258:Genes, mos; D005822:Genetic Vectors; D008969:Molecular Sequence Data; D008980:Moloney murine sarcoma virus / Q000235:genetics*; D016297:Mutagenesis, Site-Directed; D009838:Oligodeoxyribonucleotides; D017232:Oncogene Proteins v-mos; D011505:Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D015682:Retroviridae Proteins, Oncogenic / Q000235:genetics* / Q000378:metabolism; D009053:Sarcoma Viruses, Murine / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
chemical_list: D009838:Oligodeoxyribonucleotides; D017232:Oncogene Proteins v-mos; D015682:Retroviridae Proteins, Oncogenic; D011505:Protein-Tyrosine Kinases; D004229:Dithiothreitol