Phosphatase Subfamily PTPRD
Phosphatase Classification: Fold CC1: Superfamily CC1: Family PTP: Subfamily PTPRD
PTPRC (CD45) is a vertebrate-specific receptor PTP involved in immune signaling.
Evolution
PTPRC is found as a single-copy gene in all vertebrates, including the lamprey, but not in any invertebrate.
PTPRD subfamily is found in holozoan (metazoan plus it closest relative choanoflagellate). PTPRD subfamily has three gene members in most vertebrates: PTPRD, PTPRF and PTPRS. It has single member in most invertebrate metazoan. Interestingly, it expanded greatly in sponge.
Domain Structure
PTPRC has twin intracellular PTP phosphatase domains, and extracellular FN3 domains, plus a CD45-specific and a PTP-N-terminal domain found specifically in PTPRC, as annotated by InterPro. CD45 is extensively alternatively spliced.
Functions
CD45 modulates immune function [1]. It is selectively expressed on lymphocytes and dephosphorylates and activates the src family tyrosine kinases lck, fyn and lyn in B and T cells.
