v-mos protein produced by in vitro translation has protein kinase activity.
The v-mos protein, termed p37v-mos, has a closely associated serine/threonine protein kinase activity. To provide further information about its protein kinase activity, we tested the activity of p37v-mos produced in a cell-free translation system from transcripts generated from a cloned v-mos gene. Anti-mos(37-55) immunoprecipitates of in vitro-produced p37v-mos were found to possess serine/threonine protein kinase activity, whereas those obtained with anti-mos(260-271), known to block v-mos autophosphorylation, lacked kinase activity. The phosphorylated products were identical in size to p37v-mos and p43v-mos produced in protein kinase assays from Moloney murine sarcoma virus-infected cells expressing authentic p37v-mos. These results provide further proof that the protein kinase activity associated with p37v-mos is an intrinsic property of the v-mos gene product. This translation system also provides a useful experimental model to study the activation of the mos protein kinase. Thus, protein kinase assays performed on [35S]methionine-labeled p37v-mos produced p43v-mos at the expense of p37v-mos. Phosphatase treatment removed the p43v-mos species, resulting in increase of the p37v-mos-sized protein, confirming our previous interpretation that p43v-mos is a hyperphosphorylated form of p37v-mos.
Herzog
N K
NK
Department of Molecular Pathology, University of Texas M. D. Anderson Cancer Center, Houston 77030.
Nash
M
M
Ramagli
L S
LS
Arlinghaus
R B
RB
D000818:Animals; D002474:Cell-Free System; D002478:Cells, Cultured; D003001:Cloning, Molecular; D051379:Mice; D008970:Molecular Weight; D008980:Moloney murine sarcoma virus / Q000201:enzymology / Q000235:genetics*; D017232:Oncogene Proteins v-mos; D009857:Oncogenes; D010766:Phosphorylation; D010957:Plasmids; D014176:Protein Biosynthesis; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D015183:Restriction Mapping; D015682:Retroviridae Proteins, Oncogenic / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D009053:Sarcoma Viruses, Murine / Q000235:genetics*; D014158:Transcription, Genetic
D017232:Oncogene Proteins v-mos; D015682:Retroviridae Proteins, Oncogenic; D011494:Protein Kinases