Ctsk
Function
Thiol protease involved in osteoclastic bone resorption and may participate partially in the disorder of bone remodeling. Displays potent endoprotease activity against fibrinogen at acid pH. May play an important role in extracellular matrix degradation. Involved in the release of thyroid hormone thyroxine (T4) by limited proteolysis of TG/thyroglobulin in the thyroid follicle lumen.
Sequence Similarities
Belongs to the peptidase C1 family.
Cellular localization
- Lysosome
- Secreted
- Apical cell membrane
- Peripheral membrane protein
- Extracellular side
- Localizes to the lumen of thyroid follicles and to the apical membrane of thyroid epithelial cells.
Alternative names
Cathepsin K, Ctsk