Fig. 2
From: The beneficial role of proteolysis in skeletal muscle growth and stress adaptation
The role of the UPP in skeletal muscle growth. Exercise-induced protein damage via increased ROS/mechanical and heat stress necessitates an increase in proteasome-mediated proteolysis to rid the cells of non-functional myofibrillar proteins. This is typically dependent on a prerequisite increase in key muscle-specific ubiquitin ligases, MuRF1 and atrogin-1 (MAFbx), which ubiquitinate and target damaged proteins for degradation by the 26S proteasome. Efficient removal of damaged proteins is critical to skeletal muscle growth and remodeling following exercise