Expression and Function of IA-2 Family Proteins, Unique Neuroendocrine-specific Protein-tyrosine Phosphatases

Endocrine Journal

Seiji TORII¹ 

[1] Secretion Biology Lab, Institute for Molecular and Cellular Regulation, Gunma University

关键词: Insulin;    Secretory granule;    Dense-core vesicle;    Peptide hormone;    Diabetes;   

DOI  :  10.1507/endocrj.K09E-157

学科分类：内分泌与代谢学

来源: Japan Endocrine Society

【 摘 要 】

References(64)Cited-By(12)IA-2 (also known as islet cell antigen ICA-512) and IA-2β (also known as phogrin, phosphatase homologue in granules of insulinoma) are major autoantigens in insulin-dependent diabetes mellitus (IDDM). Autoantibodies against both proteins are expressed years before clinical onset, and they become predictive markers for high-risk subjects. However, the role of these genes in the IDDM pathogenesis has been reported fairly negative by recent studies. IA-2 and IA-2β are type I transmembrane proteins that possess one inactive protein-tyrosine phosphatase (PTP) domain in the cytoplasmic region, and act as one of the constituents of regulated secretory pathways in various neuroendocrine cell types including pancreatic β-cells. Existence of IA-2 homologues in different species suggests a fundamental role in neuroendocrine function. Studies of knockout animals have shown their involvement in maintaining hormone content, however, their specific steps in the secretory pathway IA-2 functions as well as their molecular mechanisms in the hormone content regulation are still unknown. More recent studies have suggested a novel function showing that they contribute to pancreatic β-cell growth. This review attempts to show the possible biological functions of IA-2 family, focusing on their expression and localization in the neuroendocrine cells.

【 授权许可】

Unknown