title: Extracellular-matrix synthesis by skeletal muscle in culture. Major secreted collagenous proteins of clonal myoblasts.
abstract: We have previously shown that G8-1, a murine clonal skeletal-muscle cell line, produces a substrate-attached extracellular matrix [Beach, Burton, Hendricks & Festoff (1982) J. Biol. Chem. 257, 11437-11442]. To examine further the expression of extracellular-matrix proteins by muscle cells, we have analysed the collagenous proteins secreted by G8-1 myoblasts. We have found that collagens and/or procollagens, corresponding to genetic types I, III and IV (and possibly V), are produced and secreted by G8-1 myoblasts. The major secreted collagenous polypeptides were identified as alpha 1 type I and its precursors by using pulse-chase studies, pepsin and collagenase digestions and CNBr fragmentation. The presence of lesser amounts of the other collagens was determined by immunoprecipitation. These results demonstrate that clonal skeletal-muscle cells, in the absence of fibroblasts and an exogenous collagen substrate, are able to synthesize and secrete several extracellular-matrix collagenous proteins in proportions similar to those which are commonly found in muscle tissue and mixed cultures of muscle cells and fibroblasts.
authors.forename: R L
authors.initials: RL
authors.lastname: Beach
authors.forename: J S
authors.initials: JS
authors.lastname: Rao
authors.forename: B W
authors.initials: BW
authors.lastname: Festoff
mesh_terms: D000818:Animals; D002460:Cell Line; D011232:Chemical Precipitation; D003094:Collagen / Q000276:immunology / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005110:Extracellular Space / Q000378:metabolism; D046911:Macromolecular Substances; D008623:Mercaptoethanol / Q000494:pharmacology; D051379:Mice; D003012:Microbial Collagenase / Q000494:pharmacology; D009124:Muscle Proteins / Q000276:immunology / Q000378:metabolism*; D009132:Muscles / Q000166:cytology; D010434:Pepsin A / Q000494:pharmacology; D010446:Peptide Fragments / Q000032:analysis
chemical_list: D046911:Macromolecular Substances; D009124:Muscle Proteins; D010446:Peptide Fragments; D008623:Mercaptoethanol; D003094:Collagen; D010434:Pepsin A; D003012:Microbial Collagenase