p34cdc2 protein is complexed with the c-mos protein in rat skeletal muscle.
We have used fractionation of subcellular components of the skeletal muscle followed by Western blot analyses to study the localization of the c-mos protein in adult rat muscle. We find that p43c-mos is predominantly located in the KCl supernatant fraction. We show that immunoprecipitates of p43c-mos phosphorylate in vitro two polypeptides of about 34 kDa and 80 kDa respectively. Muscle fractionation and immunodetection studies showed that the p34 protein associated with p43c-mos is the cdc2 protein. p43c-mos is coprecipitated with p34cdc2 when using either anti PSTAIR antibody, antibody directed against the conserved COOH terminal region of the p34cdc2 and by binding to beads that contain cross-linked p13suc1, a protein known to bind p34cdc2. Likewise p34cdc2 coprecipitated with p43c-mos when using anti mos antibody. However p43c-mos is not present in histone H1 kinase active p34cdc2 complex precipitated with anti p34cdc2 COOH-terminal peptide antibody. In adult muscle tissue tubulin is not complexed with p34cdc2 and p43c-mos as previously observed in c-mos and v-mos transformed cells. Gel filtration and crosslinking experiments show that a 170 kDa complex contains c-mos and p34cdc2 proteins. In addition during postnatal development of skeletal muscle we observe modifications in the migration pattern of p34cdc2 correlated with the accumulation of p43c-mos. Our findings raise the possibility of a p43c-mos-p34cdc2 complex could play a role in the differentiation process and maintenance of myotubes in Go.
Laboratorie d'Oncologie Moléculaire, UA 1158, URA126 du CNRS Institut Gustave Roussy, Villejuif, France.
S A
SA
Leibovitch
M
M
Guillier
J L
JL
Lenormand
M P
MP
Leibovitch
D000818:Animals; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D002451:Cell Compartmentation; D018797:Cell Cycle Proteins; D003600:Cytosol / Q000201:enzymology; D005656:Fungal Proteins / Q000378:metabolism; D009124:Muscle Proteins / Q000378:metabolism; D009132:Muscles / Q000201:enzymology*; D010750:Phosphoproteins / Q000378:metabolism; D006656:Protamine Kinase / Q000737:chemistry; D011485:Protein Binding; D011494:Protein Kinases / Q000378:metabolism*; D017231:Proto-Oncogene Proteins c-mos / Q000378:metabolism*; D051381:Rats; D029702:Schizosaccharomyces pombe Proteins
D018797:Cell Cycle Proteins; D005656:Fungal Proteins; D009124:Muscle Proteins; D010750:Phosphoproteins; D029702:Schizosaccharomyces pombe Proteins; C051655:Suc1 protein, S pombe; D011494:Protein Kinases; D006656:Protamine Kinase; D017231:Proto-Oncogene Proteins c-mos; D016203:CDC2 Protein Kinase