The protein encoded by this gene, type II matriptase, is an epithelial-derived integral membrane serine protease. This protease forms a complex with the Kunitz-type serine protease inhibitor, HAI-1, and is activated by sphingosine-1-phosphate. Matriptase has been shown to cleave and activate hepatocyte growth factor/scattering factor and urokinase plasminogen activator, suggesting the function of this protease as an epithelial membrane activator for other proteases and latent growth factors. Expression of this protease has been associated with breast, colon, prostate, and ovarian carcinomas (Kauppinen JMet al. 2010).
The transmembrane serine protease matriptase exhibits trypsin-like activity and is involved in terminal differentiation of keratinocytes through activation of prostasin (PRSS8) and processing of filaggrin(FLG).