PTP-like domain of receptor-type tyrosine-protein phosphatase N
Receptor-type tyrosine-protein phosphatase-like N (PTPRN or R-PTP-N), also called islet cell antigen 512 (ICA512) or PTP IA-2, belongs to the family of classical tyrosine-specific protein tyrosine phosphatases (PTPs). It consists of a large ectodomain that contains a RESP18HD (regulated endocrine-specific protein 18 homology domain), followed by a transmembrane segment, and a single, catalytically-impaired, PTP domain. PTPRN is located in secretory granules of neuroendocrine cells and is involved in the generation, cargo storage, traffic, exocytosis and recycling of insulin secretory granules, as well as in beta-cell proliferation. It is a major autoantigen in type 1 diabetes and is involved in the regulation of insulin secretion.
Feature 1: catalytic site [active site], 2 residue positions
Conserved feature residue pattern:C R
Evidence:
Comment:the catalytic cysteine initiates a nucleophilic attack on the phosphate group of the substrate, forming a transient phosphoenzyme intermediate and releasing the substrate dephosphorylated; the transition state is stabilized by the arginine present in the catalytic pocket
Jiyao W et al.(2023). "The conserved domain database in 2023.",