A P387L Variant in Protein Tyrosine Phosphatase-1B (PTP-1B) Is Associated With Type 2 Diabetes and Impaired Serine Phosphorylation of PTP-1B In Vitro

• Published in: Diabetes (New York, N.Y.) Vol. 51; no. 1; pp. 1 - 6
• Main Authors: Echwald, Søren M, Bach, Helle, Vestergaard, Henrik, Richelsen, Bjørn, Kristensen, Kurt, Drivsholm, Thomas, Borch-Johnsen, Knut, Hansen, Torben, Pedersen, Oluf
• Format: Journal Article
• Language: English
• Published: Alexandria, VA American Diabetes Association 01.01.2002
• Subjects: Amino Acid Substitution; Animals; Biological and medical sciences; Diabetes Mellitus, Type 2 - enzymology; Diabetes Mellitus, Type 2 - genetics; Female; Genetic aspects; Genetic polymorphisms; Genetic Variation; Genotype; Health aspects; Humans; Male; Mice; Middle Aged; Phosphorylation; Phosphoserine - metabolism; Polymerase Chain Reaction; Protein Tyrosine Phosphatase, Non-Receptor Type 1; Protein Tyrosine Phosphatases - genetics; Protein Tyrosine Phosphatases - metabolism; Reference Values; Serine - metabolism; Type 2 diabetes
• ISSN: 0012-1797; 1939-327X
• DOI: 10.2337/diabetes.51.1.1

A P387L Variant in Protein Tyrosine Phosphatase-1B (PTP-1B) Is Associated With Type 2 Diabetes and Impaired Serine Phosphorylation of PTP-1B In Vitro Søren M. Echwald 1 , Helle Bach 1 , Henrik Vestergaard 2 , Bjørn Richelsen 3 , Kurt Kristensen 3 , Thomas Drivsholm 4 , Knut Borch-Johnsen 1 , Torben Hansen 1 and Oluf Pedersen 1 1 Steno Diabetes Center and Hagedorn Research Institute, Copenhagen, Denmark 2 Department of Endocrinology, Herlev University Hospital, Herlev, Denmark 3 Department of Medicine and Endocrinology, Aarhus, Denmark 4 Centre of Preventive Medicine, Glostrup University Hospital, Glostrup, Denmark Abstract In the present study, we tested the hypothesis that variability in the protein tyrosine phosphatase-1B (PTP-1B) gene is associated with type 2 diabetes. Using single-strand conformational polymorphism analysis, we examined cDNA of PTP-1B from 56 insulin-resistant patients with type 2 diabetes as well as cDNA from 56 obese patients. Four silent variants, (NT CGA→CGG) R199R, (NT CCC→CCT) P303P, 3′UTR+104insG, and 3′UTR+86T→G, and one missense variant, P387L, were found. Subsequent analysis on genomic DNA revealed two intron variants, IVS9+57C→T and IVS9+58G→A, and two missense variants, G381S and T420M. The G381S and 3′UTR+104insG insertion variants were not associated with type 2 diabetes. In an association study, the P387L variant was found in 14 of 527 type 2 diabetic subjects (allelic frequency 1.4%, 0.4–2.4 CI) and in 5 of 542 glucose-tolerant control subjects (allelic frequency 0.5%, CI 0.1–1.1), showing a significant association to type 2 diabetes ( P = 0.036). In vitro, p34 cell division cycle (p34 cdc2 ) kinase–directed incorporation of [γ- 32 P]ATP was reduced in a mutant peptide compared with native peptide (387P: 100% vs. 387L: 28.4 ± 5.8%; P = 0.0012). In summary, a rare P387L variant of the PTP-1B gene is associated with a 3.7 (CI 1.26–10.93, P = 0.02) genotype relative risk of type 2 diabetes in the examined population of Danish Caucasian subjects and results in impaired in vitro serine phosphorylation of the PTP-1B peptide. Footnotes Address correspondence and reprint requests to Søren M. Echwald, PhD, Steno Diabetes Center and Hagedorn Research Institute, Niels Steensens vej 6, DK-2820 Gentofte, Denmark. E-mail: sme{at}hagedorn.dk . Received for publication 20 April 2001 and accepted in revised form 31 October 2001. Posted on the World Wide Web at http://www.diabetes.org/diabetes_rapids on 11 December 2001. IRS, insulin receptor substrate; p34 cdc2 , p34 cell division cycle; MBP, myelin basic protein; PCR, polymerase chain reaction; PTP-1B, protein tyrosine phosphatase-1B; SSCP, single-strand conformation polymorphism.