Comparative proteomics of skeletal muscle mitochondria from myostatin‐null mice

Myostatin, a secreted protein, is a negative regulator of skeletal muscle growth. Down‐regulating its expression increases skeletal muscle mass that is accompanied by a marked change in the fibre composition from one reliant on mitochondrial oxidative metabolism to glycolysis. A comparative proteomic investigation of this altered metabolism was carried out on mitochondria from the gastrocnemius muscle of myostatin‐null mice compared with wild‐type. Most of the proteins identified showed no significant modulation between the 2 phenotypes, but give interesting insight into previous observations. Several proteins were modulated, of which only one was identified. This protein, having a sequence similar to that of aldehyde reductase, was up‐regulated in myostatin‐null mitochondria, but its importance was not established, although it might play a role in the detoxification of harmful products of lipid peroxidation.