Abstract
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.
Publication types
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Comparative Study
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Research Support, Non-U.S. Gov't
MeSH terms
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Actins / biosynthesis
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Actins / isolation & purification
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Actins / metabolism
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Animals
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Autoradiography
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Cells, Cultured
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Electrophoresis, Gel, Two-Dimensional
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Kinetics
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Methionine / metabolism
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Mice
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Mice, Inbred C57BL
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Mice, Mutant Strains
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Muscle Proteins / biosynthesis
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Muscle Proteins / isolation & purification
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Muscle Proteins / metabolism*
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Muscles / cytology
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Muscles / metabolism*
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Muscles / pathology
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Muscular Dystrophy, Animal / metabolism*
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Proton-Translocating ATPases / biosynthesis
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Proton-Translocating ATPases / isolation & purification
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Proton-Translocating ATPases / metabolism
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Sulfur Radioisotopes
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Tubulin / biosynthesis
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Tubulin / isolation & purification
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Tubulin / metabolism*
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Vimentin / biosynthesis
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Vimentin / isolation & purification
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Vimentin / metabolism
Substances
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Actins
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Muscle Proteins
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Sulfur Radioisotopes
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Tubulin
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Vimentin
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Methionine
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Proton-Translocating ATPases