**4. Conclusions and perspectives**

Recent progress has significantly expanded our understanding of the molecular mechanisms that regulate skeletal muscle protein synthesis and degradation. Despite this, considerably more research is required to fully elucidate the many different mechanisms that potentially regulate these two processes. Successful identification of common regulatory molecules/ pathways will greatly aid our understanding of how different types of stimuli promote changes in skeletal muscle mass. The Akt/mTOR/p70S6K pathway and SRF-dependent signaling have been considered to be major contributors to protein synthesis and musclespecific transcription, respectively [11, 23]. Over the past decade, studies using rodent muscles have indicated that atrogin-1 and MuRF-1 contribute to the protein degradation in muscular wasting [60]. More recent studies using human muscle do not necessarily support such a role for these atrogenes [77]. It seems that the disorganization of the autophagy system accelerates the muscular disorder with age (sarcopenia) in rodents and human.
