Islet cell antigen 512 is a diabetes-specific islet autoantigen related to protein tyrosine phosphatases.
Islet cell Ag 512 (ICA512) is a recombinant human Ag that was isolated from an islet cDNA expression library by screening with human insulin-dependent diabetes mellitus sera. Specificity of reaction with diabetic sera was demonstrated initially by immunoprecipitation with a small number of diabetic and normal serum samples. To permit quantitative and rapid serum testing, ICA512 was purified and adapted to an ELISA format. In this way, a sensitivity of 48% with newly diagnosed diabetic sera has been measured with a panel of 80 sera. DNA sequencing of ICA512-3, a cDNA that contains a 1644 bp open reading frame, suggests that it codes for a transmembrane protein having a single membrane-spanning segment and a cytoplasmic domain that is closely related to the first intracellular (catalytic) domain of the T cell protein tyrosine phosphatase, CD45. Northern blot analysis of poly(A)+ RNAs from several human tissues indicates that ICA512 mRNA is expressed in brain and pancreas.
Rabin
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Institute for Metabolic Disorders, Miles Research Center, West Haven, CT 06516.
Pleasic
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Shapiro
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Yoo-Warren
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Oles
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Hicks
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Goldstein
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Rae
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D000595:Amino Acid Sequence; D001324:Autoantigens / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D003920:Diabetes Mellitus / Q000276:immunology*; D006801:Humans; D007515:Islets of Langerhans / Q000276:immunology*; D008969:Molecular Sequence Data; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry*; D012333:RNA, Messenger / Q000032:analysis; D017386:Sequence Homology, Amino Acid
D001324:Autoantigens; D012333:RNA, Messenger; D017027:Protein Tyrosine Phosphatases