The role of ubiquitin–proteasome-dependent proteolysis in the remodelling of skeletal muscle

Abstract

In skeletal muscle, as in any mammalian tissue, protein levels are dictated by relative rates of protein synthesis and breakdown. Recent studies have shown that the ubiquitin-proteasome-dependent proteolytic pathway is mainly responsible for the breakdown of myofibrillar proteins. In this pathway proteins that are to be degraded are first tagged with a polyubiquitin degradation signal. Ubiquitination is performed by the ubiquitin-activating enzyme, ubiquitin-conjugating enzymes and ubiquitin-protein ligases, which are responsible for the recognition of specific substrates. Polyubiquitinated protein substrates are then specifically recognised and degraded by the 26S proteasome. The present review focuses on: (1) the mechanisms of ubiquitination-deubiquitination that make the system highly selective; (2) the mechanisms of proteolysis in skeletal muscle. In particular, the role of the system in the remodelling of skeletal muscle during exercise and disuse and in recovery or regeneration that prevails during post-atrophic conditions is reviewed.

The impact of growth promoters on muscle growth and the potential consequences for meat quality

“…Proteolysis by the proteasome is an ubiquitin-dependent process; poly-ubiquitinated proteins are subsequently recognised by the proteasome, which then degrades them (Taillandier et al, 2004). This process is ATP-dependent requiring a number of enzymes to ubiquitinate target proteins.…”

Physical activity and health, novel concepts and new targets: report from the 12th Conference of the International Research Group on the Biochemistry of Exercise

“…This topic was covered by Dr Attaix (Taillandier et al 2004). The ubiquitin-proteasome-dependent proteolytic machinery is one of the major proteolytic systems in the skeletal muscle.…”

Correlation between the Presence of Ubiquitin Conjugated Protein Phosphatase Inhibitor 1 and Postmortem Muscle Glycogen Metabolism

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