Cysteine Proteases and Regulators

As the two major families of cysteine proteases, Caspases are cytosolic, asparate-specific and involved in apoptosis whereas Cathepsins are mainly lysosomal, active under acidic conditions and involved in protein degradation. Legumain and Separase are two newer proteases with the specificity for Asn residue and Cohesin, respectively. Known protein inhibitors of the cysteine proteases are members of Cystatin, IAP, Testican and Lipocalin families.