Cathepsin research is one of the most progressive areas in proteolysis. Cathepsins are a diverse group of eukaryotic peptidases belonging to the aspartic, cysteine and serine classes.
They act as both non-specific proteases and as specific processing enzymes in numerous physiological and pathological processes. In humans, their dysregulation is associated with severe pathologies, such as cancer, cardiovascular and neurodegenerative diseases, arthritis, and osteoporosis.
Proteolytic systems controlled by cathepsins are a critical part of host-pathogen and host-parasite interactions as demonstrated for cathepsin-like peptidases from, e.g., hematophagous parasites, herbivorous insects and plants. Because of the broad involvement of cathepsins in pathological processes, they are among today's top-priority drug targets.
This review provides an update on the structure and function of pathology-associated cathepsins in humans and human parasites.