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

Access this Article

Search this Article

Author(s)

    • TORII SEIJI
    • Secretion Biology Lab, Institute for Molecular and Cellular Regulation, Gunma University

Abstract

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.

Journal

  • Endocrine Journal

    Endocrine Journal 56(5), 639-648, 2009-08-20

    The Japan Endocrine Society

References:  64

Cited by:  1

Codes

  • NII Article ID (NAID)
    10026914419
  • NII NACSIS-CAT ID (NCID)
    AA10901436
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    09188959
  • Data Source
    CJP  CJPref  J-STAGE 
Page Top