Human Protein Tyrosine Phosphatase Receptor Type N (PTPRN) Protein

Background

PTPRN, also known as IA-2, is a receptor-like protein tyrosine phosphatase predominantly expressed in neuroendocrine tissues, particularly in pancreatic β-cells. Structurally, it features a single transmembrane domain and an intracellular region that lacks phosphatase activity due to critical residue substitutions. PTPRN functions as a key regulator of insulin secretion and is essential for the formation and stability of secretory granules in endocrine cells. It interacts with granule components to facilitate the docking and exocytosis of insulin and other hormones. PTPRN is also an autoantigen in type 1 diabetes mellitus (T1DM), where autoimmune responses against it lead to β-cell destruction. Its role in neuroendocrine cell function emphasizes its importance in glucose homeostasis and diabetes pathogenesis. Mutations or dysregulation of PTPRN have been implicated in metabolic disorders and neurodegenerative diseases.