Regulation of skeletal muscle cell plasticity by the peroxisome proliferator-activated receptor gamma coactivator 1alpha

Exercise triggers a pleiotropic response in skeletal muscle, which results in a profound remodeling of this tissue. Physical activity-dependent muscle fiber plasticity is regulated by a number of distinct signaling pathways. Even though most of these pathways are activated by different stimuli and in a temporally and spatially separated manner during exercise, many of the major signal transduction events converge on the peroxisome proliferator-activated receptor gamma coactivator 1alpha (PGC-1alpha) by post-translationally modifying the PGC-1alpha protein, modulating PGC-1alpha gene expression or both. In turn, depending on the cellular context, PGC-1alpha regulates specific gene programs. Ultimately, PGC-1alpha modulates most of the transcriptional adaptations of skeletal muscle to exercise. In this review, the regulation and function of this pivotal transcriptional coactivator in muscle are discussed.