Diabetologia

, Volume 38, Issue 4, pp 461–466

Molecular and linkage analysis of type-1 protein phosphatase catalytic beta-subunit gene: lack of evidence for its major role in insulin resistance in Pima Indians

  • M. Prochazka
  • H. Mochizuki
  • L. J. Baier
  • P. T. W. Cohen
  • C. Bogardus
Originals

Summary

Insulin resistance is believed to be a prediabetic condition that results from reduced rates of insulin-mediated glycogen synthesis in skeletal muscle. A decrease in activities of skeletal muscle glycogen synthase and of its regulatory enzyme type-1 protein phosphatase (PP 1) have been previously identified in insulin-resistant Pima Indians. Because the PP1 catalytic Β-subunit is presumed to be the major isoform in the glycogen-bound PP1 complex, we have selected the structural gene for this subunit (PPP1CB) as a candidate for a detailed genetic analysis. We have determined the exon-intron structure of PPP1CB, and have identified a polymorphic (CA)-repeat marker (D2S1237) at this gene. No sequence abnormalities were detected in PPP1CB by Southern blot analysis or by single-stranded conformational polymorphism analysis of all eight coding exons. Using sib-pair linkage analyses, no evidence for linkage was found between the D2S1237 marker at this locus and fasting insulin, insulin-stimulated glucose uptake in vivo, obesity, or non-insulin-dependent diabetes mellitus. Similarly, we have found no evidence for association of D2S1237 with any of these phenotypes. Based on our data we conclude that the structural gene for the PP1 catalytic Β-subunit does not appear to be a major genetic determinant responsible for the PP1 abnormalities characteristic of insulin resistance in Pima Indians.

Key words

Insulin resistance type-1 protein phosphatase PP1Β catalytic subunit gene Pima Indians 

Abbreviations

NIDDM

Non-insulin-dependent diabetes mellitus

PP1

type-1 protein phosphatase

PPP1CB

type-1 protein phosphatase catalytic Β-subunit gene

SSCP

single-stranded conformational polymorphism

PCR

polymerase chain reaction

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References

  1. 1.
    DeFronzo RA, Bonadonna RC, Ferrannini E (1992) Pathogenesis of NIDDM. A balanced overview. Diabetes Care Reviews 15: 318–368Google Scholar
  2. 2.
    Bogardus C, Lillioja S, Bennett PH (1991) Pathogenesis of NIDDM in Pima Indians. Diabetes Care 14 [Suppl 3]: 685–690Google Scholar
  3. 3.
    Mott DM, Kida Y, Nyomba BL (1993) Human skeletal muscle, type-1 protein phosphatase and insulin resistance. Adv Prot Phosphatases 7: 413–427Google Scholar
  4. 4.
    Kida Y, Esposito-Del Puente A, Bogardus C, Mott DM (1990) Insulin resistance is associated with reduced fasting and insulin-stimulated glycogen synthase phosphatase activity in human skeletal muscle. J Clin Invest 85: 476–481Google Scholar
  5. 5.
    Cohen P (1989) The structure and regulation of protein phosphatases. Ann Rev Biochem 58: 453–508Google Scholar
  6. 6.
    Barker HM, Jones TA, da Cruz e Silva EF, Spurr NK, Sheer D, Cohen PTW (1990) Localization of the gene encoding type 1 protein phosphatase catalytic subunit to human chromosome band 11q13. Genomics 7: 159–166Google Scholar
  7. 7.
    Barker HM, Craig SP, Spurr NK, Cohen PTW (1993) Sequence of protein serine/threonine phosphatase 1 gamma and localisation of the gene (PPP1CC) encoding it to chromosome bands 12q24.1-q24.2. Biochim Biophys Acta 1278: 228–233Google Scholar
  8. 8.
    Shima H, Hatano Y, Chun Y-S et al. (1993) Identification of PP1 catalytic subunit isotypes in various rat tissues. Biochim Biophys Res Comm 192: 1289–1296Google Scholar
  9. 9.
    Barker HM, Brewis ND, Street AJ, Spurr NK, Cohen PTW (1994) Three genes for protein phosphatase I map to different human chromosomes: sequence, expression and gene localisation of protein serine/threonine phosphatase 1 beta (PPP1CB). Biochim Biophys Acta 1220: 212–218Google Scholar
  10. 10.
    Alessi DR, Street AJ, Cohen P, Cohen PTW (1993) Inhibitor-2 functions like a chaperone to fold three expressed isoforms of mammalian protein phosphatase-1 into a conformation with the specificity and regulatory properties of the native enzyme. Eur J Biochem 213: 1055–1066Google Scholar
  11. 11.
    Dombrádi V, Axton JM, Brewis ND, da Cruz e Silva EF, Alphey L, Cohen PTW (1990) Drosophila contains three genes that encode distinct isoforms of protein phosphatase 1. Eur J Biochem 194: 739–745Google Scholar
  12. 12.
    Cohen PTW (1990) The molecular biology of protein serine/threonine phosphatases regulating metabolism. In: Randle PJ, Bell J, Scott J (eds) Genetics and Human Nutrition. John Libbey, London, pp 27–40Google Scholar
  13. 13.
    Prochazka M, Lillioja S, Tait JF et al. (1993) Linkage of chromosomal markers on 4q with a putative gene determining maximal insulin action in Pima Indians. Diabetes 42: 514–519Google Scholar
  14. 14.
    Spurr NK (1992) Standards for reporting alleles at highly polymorphic loci: a proposal. Human Molecular Genetics 1: 211–212Google Scholar
  15. 15.
    Tagle DA, Collins FS (1992) An optimized Alu-PCR primer pair for human-specific amplification of YACs and somatic cell hybrids. Human Molecular Genetics 1: 121–122Google Scholar
  16. 16.
    Pandolfo M (1992) A rapid method to isolate (GT)n repeats from yeast artificial chromosomes. Nucleic Acids Res 20: 1154Google Scholar
  17. 17.
    Prochazka M, Serreze DV, Worthen SM, Leiter EH (1989) Genetic control of diabetogenesis in NOD/Lt mice: development and analysis of congenic stocks. Diabetes 38: 1446–1455Google Scholar
  18. 18.
    Ott J (1991) Methods of linkage analysis: nonparametric approaches. In: Analysis of human genetic linkage (revised ed) Johns Hopkins University Press, Baltimore, pp 77–80Google Scholar
  19. 19.
    Breathnach R, Chambon P (1981) Organization and expression of eukaryotic split genes coding for proteins. Ann Rev Biochem 50: 349–383Google Scholar
  20. 20.
    Bjorbaek C, Echwald S, Richmond K et al. (1993) Variants in the promoter and coding sequence of genes encoding key proteins in insulin stimulated glycogen synthesis of muscle from NIDDM patients. Diabetologia 36: A83 (Abstract)Google Scholar
  21. 21.
    Cohen PTW, Cohen P (1989) Discovery of a protein phosphatase activity encoded in the genome of bacteriophage λ. Biochem J 260: 931–934Google Scholar
  22. 22.
    Khew-Goodhall Y, Mayer RE, Maurer F, Stone SR, Hemmings BA (1991) Structure and transcriptional regulation of protein phosphatase 2A catalytic subunit genes. Biochemistry 30: 89–97Google Scholar

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • M. Prochazka
    • 1
  • H. Mochizuki
    • 1
  • L. J. Baier
    • 1
  • P. T. W. Cohen
    • 2
  • C. Bogardus
    • 1
  1. 1.Clinical Diabetes and Nutrition SectionNational Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthPhoenixUSA
  2. 2.Department of Biochemistry, Medical Research Council Protein Phosphorylation UnitUniversity of DundeeDundeeUK

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