Matriptases

Matriptases belong to the type 2 trasmembranous serine proteases, a heterogeneous enzyme family with 4 members: n

• matriptase/MTSP-1 (chromosome 11q25). MTSP-1 consists in its extracellular structure of a serine protease domain, 4 LDL-receptor class A domains and two CUB regions. The serine portease is mainly expressed in human epithelia. Loss of enzyme function plays an important role in the exfoliation process of the stratum corneum of the epidermis. A reduced proteolytic activation of prostasin and a disturbed processing of profile aggrin has been proven. The consequence is retention hyperkeratosis of the epidermis. The clinical picture of "ichthyosis-hypotrichosis syndrome", a moderately severe lamellar ichthyosis, is caused by different autosomal recessive mutations in the matriptase-1 gene.
• Matriptase-2 (chromosome 22q12-q13): Mutations in matriptase gene 2 with loss of matriptase 2 protein function correlated with tumor progression in breast cancer in a Finnish population. (Hartikainen JM et al. 2006). Cheng et al. found tumor progressions in oral squamous cell carcinoma with function losses of this serine protease.
• Matriptase-3 (chromosome 3q13.2): The biological function of the transmembrane serine protease matriptase-3, whose coding gene is located on chromosome 3q13.2, is still largely unknown (Szabo R et al. 2005)
• Polyserase-1 (function still largely unknown; possible role in tumor progression)

Serine proteases include the digestive enzymes: trypsin, chymotrypsin, elastase, plasmin and thrombin. Currently, 45 families of serine proteases are known.

1. Cheng MF et al (2017) Downexpression of Matriptase-2 Correlates With Tumor Progression and Clinical Prognosis in Oral Squamous-Cell Carcinoma. Appl Immunohistochem Mol Morphol 25:481-488.
2. Fontanil T et al (2014) Polyserase-1/TMPRSS9 induces pro-tumor effects in pancreatic cancer cells by activation of pro-uPA. Oncol Rep 31:2792-2796.
3. Hartikainen JM et al (2006) Refinement of the 22q12-q13 breast cancer--associated region: evidence of TMPRSS6 as a candidate gene in an eastern Finnish population. Clin Cancer Res 12:1454-1462.
4. Szabo R et al (2005) Matriptase-3 is a novel phylogenetically preserved membrane-anchored serine protease with broad serpin reactivity. Biochem J 390:231 242.