Transcriptional regulation in response to exercise.

Much progress has been made in recent years into understanding molecular mechanisms by which transcription is regulated following changes in physiological stimuli. This review has tried to focus on what is known about four specific physiological challenges--mechanical load, intracellular calcium, hypoxia, and redox state. Because of our biased interest in exercise, it was our goal to review these relatively well-studied systems so that we might provide insight into potential mechanisms that govern exercise-induced transcriptional changes. What becomes obvious, when reaching the end of this review, is that there are many common themes among the different physiological responses described. Some examples include the activation of IEGs, such as c-jun and c-fos, the phosphorylation of the transcription factor CREB, and the importance of the serum response element and the serum response factor. These commonalities across the different physiological systems suggest a certain redundancy or shared mechanism(s) for regulating transcription in response to physiological stimuli. While very little is known at this time about how exercise regulates transcription, it is an exciting time in this field of research. The recent growth in the molecular biological research literature of more physiologically-based studies provides exciting new molecular and cellular tools for those researchers willing to take on the challenge of understanding the complex mechanisms of exercise-induced adaptations.