Discordant skeletal muscle gene and protein responses to exercise

Regular exercise leads to many adaptations, including changes to protein abundance, which serve to blunt subsequent homeostatic threats generated by future skeletal muscle contractions.The exercise biology field has developed its own dogma, which proposes that transient changes in mRNA after a single session of exercise can provide insights into both the direction and magnitude of protein changes likely to occur following training.However, there are examples of contraction-induced changes in mRNA without any subsequent change in encoded proteins, and, conversely, proteins with increased abundance in response to exercise training without a corresponding change in respective mRNA levels.We propose an alternative view that there is not always a direct relationship between exercise-induced changes in mRNA levels and the abundance of proteins they encode. The ability of skeletal muscle to adapt to repeated contractile stimuli is one of the most intriguing aspects of physiology. The molecular bases underpinning these adaptations involve increased protein activity and/or expression, mediated by an array of pre- and post-transcriptional processes, as well as translational and post-translational control. A longstanding dogma assumes a direct relationship between exercise-induced increases in mRNA levels and subsequent changes in the abundance of the proteins they encode. Drawing on the results of recent studies, we dissect and question the common assumption of a direct relationship between changes in the skeletal muscle transcriptome and proteome induced by repeated muscle contractions (e.g., exercise). The ability of skeletal muscle to adapt to repeated contractile stimuli is one of the most intriguing aspects of physiology. The molecular bases underpinning these adaptations involve increased protein activity and/or expression, mediated by an array of pre- and post-transcriptional processes, as well as translational and post-translational control. A longstanding dogma assumes a direct relationship between exercise-induced increases in mRNA levels and subsequent changes in the abundance of the proteins they encode. Drawing on the results of recent studies, we dissect and question the common assumption of a direct relationship between changes in the skeletal muscle transcriptome and proteome induced by repeated muscle contractions (e.g., exercise).