Specific functions of lysosomal proteases in endocytic and autophagic pathways

13.07.2012

Müller S, Dennemärker J, Reinheckel T.

Biochim Biophys Acta. 2012;1824(1):34-43

Biochim Biophys Act          online article

Endolysosomal vesicles form a highly dynamic multifunctional cellular compartment that contains multiple highly potent proteolytic enzymes. Originally these proteases have been assigned to cooperate solely in executing the unselective ‘bulk proteolysis’ within the acidic milieu of the lysosome. Although to some degree this notion still holds true, evidence is accumulating for specific and regulatory functions of individual ‘acidic’ proteases in many cellular processes linked to the endosomal/lysosomal compartment. Here we summarize and discuss the functions of individual endolysosomal proteases in such diverse processes as the termination of growth factor signaling, lipoprotein particle degradation, infection, antigen presentation, and autophagy. Loss of cathepsin L results in impaired autophagy termination and accumulation of vesicles containing undigested materials.