Anti-PTK7 Antibody, clone 31G9 clone 31G9, from rat

Inactive tyrosine-protein kinase 7 (UniProt: Q13308; also known as Colon carcinoma kinase 4, CCK-4, Protein-tyrosine kinase 7, Pseudo tyrosine kinase receptor 7, Tyrosine-protein kinase-like 7, PTK7) is encoded by the PTK7 (also known as CCK4) gene (Gene ID: 5754) in human. PTK7 is a single-pass type I membrane protein that lacks the catalytic activity. It is highly expressed in lung, liver, pancreas, kidney, placenta and melanocytes. It is weakly expressed in thyroid gland, ovary, brain, heart and skeletal muscle. Its expression is reported to be higher in cell lines established from normal non-tumorigenic tissues compared those from highly metastatic invasive carcinomas. Six isoforms of PTK7 have been described that are generated by alternative splicing. It is synthesized with a signal peptide (aa 1-30), which is subsequently cleaved off to generate mature form. It contains seven Ig-like-C2 type domains. It has an extracellular domain (aa31-704), a transmembrane domain (aa 705-725; and a cytoplasmic domain (aa 726-1070). PTK7 is shown to associate with receptor tyrosine kinase-like orphan receptor 2 (ROR2) to form a heterodimeric complex in mammalian cells and PTK7 and ROR2 physically and functionally interact with the non-canonical WNT5A ligand leading to JNK activation and cell movements. PTK7 is cleaved by MMP14 between Pro 621 and Leu 622 to generate an N-terminal soluble (70 kDa) fragment and a membrane C-terminal (50 kDa) fragment. (Ref.: Martinez, S., et al. (2015). J. Biol. Chem. 290(51); 30562-72).