Alterations of protein degradation and 2-D protein pattern in muscle cells of MDX and DMD origin.
Intracellular protein turnover of MDX, DMD and normal muscle was determined by [35S]methionine pulse-chase experiments and subsequent high resolution 2-D gel electrophoresis. In MDX myotubes intracellular degradation of short-lived and long-lived proteins was markedly increased by a factor of 1,4-2,1. In wildtype the rate of degradation of short-lived proteins was approximately 2.6%/h, whereas in MDX these proteins were degraded by 5.7%/h. Long-lived proteins were degraded in wildtype at a rate of 1.8%/h, and in MDX at a rate of 2.5%/h. Furthermore, we have described a 51.000 Da protein with an IEP of 5.1 (p51/5.1), whose net content is highly and specifically reduced in cultured MDX and DMD muscle cells as well as in isolated MDX muscle fibers. Treatment with calcium-channel blockers Dantrolene and Verapamil inhibited the degradation of p51/5.1 in MDX myotubes by more than 90% in contrast to controls.
Kämper
A
A
Developmental Biology Unit, University of Bielefeld, Germany.
Rodemann
H P
HP
D000199:Actins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism; D000818:Animals; D001345:Autoradiography; D002478:Cells, Cultured; D015180:Electrophoresis, Gel, Two-Dimensional; D007700:Kinetics; D008715:Methionine / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D009124:Muscle Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism*; D009132:Muscles / Q000166:cytology / Q000378:metabolism* / Q000473:pathology; D009137:Muscular Dystrophy, Animal / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism; D013462:Sulfur Radioisotopes; D014404:Tubulin / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism*; D014746:Vimentin / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism
D000199:Actins; D009124:Muscle Proteins; D013462:Sulfur Radioisotopes; D014404:Tubulin; D014746:Vimentin; D008715:Methionine; D006180:Proton-Translocating ATPases