Intended Use
For In Vitro Diagnostic Use
Summary and Explanation
Cathepsin K is a cysteine protease, which may be secreted as a pro-enzyme and is activated in a low-pH environment such as lysosomes. Cathepsin K accepts Arg and Lys residues at the P1 active site, acting on Proteolytically Activated Receptors (PARs) in extracellular matrix. Cathepsin K also cleaves collagen and degrades bone matrix, and is involved in the mTOR signaling pathway of cellular autophagy and apoptosis. Cathepsin K has also been shown to play a role in MHC II antigen presentation, keratinocyte differentiation, platelet aggregation, and in the Hedgehog signaling pathway.
As a protease active in the extracellular matrix and lysosomes, Cathepsin K has been implicated in cancer progression and invasiveness. Cathepsin K has been shown to have specific proteolytic activity on PAR-3 and PAR-4, which are expressed in the EMC of epithelial-mesenchymal cells in breast cancer. Proteolytic cleavage of PARs stimulates platelet aggregation and p38 phosphorylation in the MAPK pathway.
Cathepsin K-induced proteolytic cleavage induces upregulation of proteins related to metastasis in bone and prostate cancer, and epithelial-mesenchymal-like cells in breast cancer.
Synonyms: CTSK, anti-cathepsin K, anti cathepsin K, anti-CTSK, anti CTSK, cathepsin K, cathepsin O, cathepsin O1, Cathepsin O2, cathepsin X