Limited and digestive proteolysis: crosstalk between evolutionary conserved pathways

Abstract

(Table presented.). Summary: Proteases can either digest target proteins or perform the so-called ‘limited proteolysis’ by cleaving polypeptide chains at specific site(s). Autophagy and the ubiquitin–proteasome system (UPS) are two main mechanisms carrying out digestive proteolysis. While the net outcome of digestive proteolysis is the loss of function of protein substrates, limited proteolysis can additionally lead to gain or switch of function. Recent evidence of crosstalk between autophagy, UPS and limited proteolysis indicates that these pathways are parts of the same proteolytic nexus. Here, we focus on three emerging themes within this area: limited proteolysis as a mechanism modulating autophagy; interplay between autophagy and UPS, including autophagic degradation of proteasomes (proteophagy); and specificity of protein degradation during bulk autophagy.