Human TMPRSS9 Antibody

TMPRSS9 (Transmembrane protease, Serine 9; also Polyserine protease 1) is a 116-120 kDa (predicted) member of the TTSP family of membrane-bound serine proteases. It is expressed in fetal tissue, and converts pro-uPA into its active form. Human TMPRSS9 is a 1059 type II transmembrane (TM) protein. It has a 29 aa N-terminal cytoplasmic region and a 1008 aa extracellular domain (ECD) (aa 51-1059). The ECD contains one LDLR region (aa 153-190), followed by three Peptidase S1 domains (aa 203-436, 504-736, and 827-1058), the first two of which are catalytically active. Proteolytic cleavage can generate a soluble 34 kDa Serase 1 (aa 203-503), a 35 kDa Serase 2 (aa 504-826) and an inactive 25 kDa Serase 3 (aa 827-1059). Alternatively, truncated, TM forms of TMPRSS9 such as a 56 kDa TM isotype containing only the Serase 1 domain,  or a 91 kDa (predicted) form containing the Serase 1, 2 and 3 domains may exist. Two potential splice forms are reported. One shows an insertion of 34 aa after Lys90 accompanied by a seven aa substitution for aa 491-1059. A second isoform shows a 34 aa substitution for aa 822-1059. Over aa 190-490, human TMPRSS9 shares 79% aa identity with mouse TMPRSS9.