title: Expression of sarcomeric proteins and assembly of myofibrils in the putative myofibroblast cell line BHK-21/C13.
abstract: The expression and organization patterns of several myofibrillar proteins were analysed in the putative myofibroblast cell line BHK-21/C13. Although this cell line originates from renal tissue, the majority of the cells express titin. In these cells, titin is, under standard culture conditions, detected in myofibril-like structures (MLSs), where it alternates with non-muscle myosin (NMM). Expression of sarcomeric myosin heavy chain (sMyHC) is observed in a small minority of cells, while other sarcomeric proteins, such as nebulin, myosin binding protein C (MyBP-C), myomesin and M-protein are not expressed at all. By changing the culture conditions in a way equal to conditions that induce differentiation of skeletal muscle cells, a process reminiscent of sarcomerogenesis in vitro is induced. Within one day after the switch to a low-nutrition medium, myofibrillar proteins can be detected in a subset of cells, and after two to five days, all myofibrillar proteins examined are organized in typical sarcomeric patterns. Frequently, cross-striations are visible with phase contrast optics. Transfection of these cells with truncated myomesin fragments showed that a specific part of the myomesin molecule, known to contain a titin-binding site, binds to MLSs, whereas other parts do not. These results demonstrate that this cell line could serve as a powerful model to study the assembly of myofibrils. At the same time, its transfectability offers an invaluable tool for in vivo studies concerning binding properties of sarcomeric proteins.
authors.affiliation: Department of Cell Biology, University of Potsdam, Germany. pvdven@rz.uni-potsdam.de
authors.forename: P F
authors.initials: PF
authors.lastname: van der Ven
authors.forename: D O
authors.initials: DO
authors.lastname: Fürst
mesh_terms: D000818:Animals; D001665:Binding Sites; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D064211:Connectin; D006224:Cricetinae; D003470:Culture Media / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D007668:Kidney; D008647:Mesocricetus; D008856:Microscopy, Fluorescence; D009124:Muscle Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D009194:Myeloma Proteins; D009210:Myofibrils / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000096:biosynthesis / Q000235:genetics; D011494:Protein Kinases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012518:Sarcomeres / Q000378:metabolism*; D014162:Transfection; D000099163:Myosin Binding Protein C
chemical_list: D002352:Carrier Proteins; D064211:Connectin; D003470:Culture Media; D009124:Muscle Proteins; D009194:Myeloma Proteins; D018995:Myosin Heavy Chains; D011494:Protein Kinases; D011993:Recombinant Fusion Proteins; D000099163:Myosin Binding Protein C; C085016:multiple myeloma M-proteins; C035620:nebulin