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.