PTPRK: Proteins and Enzymes

PTP kappa (PTPRK)is a member of the protein tyrosine phosphatase (PTP) family. The family comprises at least 37 proteins, characterized by a catalytic phosphatase domain of approximately 240 amino acids, and includes both transmembrane and cytosolic enzymes. PTP kappa is c-transmembrane PTP. The PTPs have high substrate specificity for phosphotyrosyl proteins and, at the primary sequence level, share little similarity with the protein serine phosphatases, protein threonine phosphatases, or the acid and alkaline phosphatases. PTP kappa is involved in the regulation of processes involving cell contact and adhesion, tumour invasion and metastasis. Regulation of processes involving cell contact and adhesion such as growth control. tumor invasion. and metastasis. Forms complexes with beta-catenin and gamma-catenin/plakoglobin. Beta-catenin may be a substrate for the catalytic activity of PTP-kappa.