Thiol protease which is believed to participate in intracellular degradation and turnover of proteins (By similarity). Cleaves matrix extracellular phosphoglycoprotein MEPE (By similarity). Involved in the solubilization of cross-linked TG/thyroglobulin in the thyroid follicle lumen (By similarity). Has also been implicated in tumor invasion and metastasis (By similarity).
Subcellular locations: Lysosome, Melanosome, Secreted, Extracellular space, Apical cell membrane
Localizes to the lumen of thyroid follicles and to the apical membrane of thyroid epithelial cells.