Synthesis and secretion of a 38-kDa glycopolypeptide coincides with L6 myoblast fusion.
Rat L6 myoblastic cell line fused rapidly after two day cultivation in a medium containing horse serum and insulin. We analyzed whether the induction of plasma membrane or secreted proteins occurred simultaneously with ongoing fusion. Thus the cells were metabolically labeled with [35S]methionine followed by biotinylation of the cell surface proteins. Detergent-solubilized proteins derivatized with biotin were isolated with streptavidin-agarose and subjected to SDS polyacrylamide gel electrophoresis. This analysis did not show fusion-associated induction of any surface proteins. However, analysis of the microsomal fraction revealed a fusion-associated 38-kDa glycopolypeptide. This polypeptide appeared simultaneously with the formation of the multinucleated cells and then declined with decreasing fusion activity. Pulse-chase labeling experiments showed that the 38-kDa component was secreted into the medium. These results indicate that a secreted protein component is induced during the fusion of L6 myoblasts.
Department of Anatomy, University of Oulu, Finland.
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Metsikkö
H K
HK
Väänänen
D000818:Animals; D002459:Cell Fusion / Q000187:drug effects / Q000502:physiology*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003402:Creatine Kinase / Q000096:biosynthesis; D003470:Culture Media; D004591:Electrophoresis, Polyacrylamide Gel; D006020:Glycopeptides / Q000096:biosynthesis* / Q000302:isolation & purification; D007328:Insulin / Q000494:pharmacology; D007700:Kinetics; D008565:Membrane Proteins / Q000096:biosynthesis / Q000302:isolation & purification; D008715:Methionine / Q000378:metabolism; D008861:Microsomes / Q000378:metabolism; D008970:Molecular Weight; D009132:Muscles / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D013997:Time Factors
D003470:Culture Media; D006020:Glycopeptides; D007328:Insulin; D008565:Membrane Proteins; D008715:Methionine; D003402:Creatine Kinase