Enhancement of Insulin Responsiveness by Nitric Oxide-mediated Inactivation of Protein-tyrosine Phosphatases
Resource
JOURNAL OF BIOLOGICAL CHEMISTRY, 285(11), 7919-7928
Journal
Journal of Biological Chemistry
Pages
7919-7928
Date Issued
2010
Date
2010
Author(s)
Hsu, Ming-Fo
Meng, Tzu-Ching
Abstract
NO synthesis is a prerequisite for proper insulin sensitivity in insulin-targeted tissues; however, the molecular basis for this process remains unclear. Using a gain-of-function model of endothelial nitric-oxide synthase (eNOS)-transfected COS-7 cells, we have shown a critical role of NO in insulin responsiveness, as evidenced by an NO-dependent increase of tyrosine phosphorylation levels of the insulin receptor and its down-stream effectors insulin receptor substrate-1 and PKB/AKT.We hypothesized that NO-induced inactivation of endogenous protein-tyrosine phosphatases (PTPs) would enhance insulin receptor-mediated signaling. To test this hypothesis, we devised a new method of the PTP labeling using a cysteine sulfhydryl-reacted probe. Under the acidic conditions employed in this study, the probe recognized the reduced and active forms but not the S-nitrosylated and inactive forms of endogenous PTPs. Our data suggest that phosphatases SHP-1, SHP-2, and PTP1B, but not TC-PTP, are likely S-nitrosylated at the active site cysteine residue concomitantly with a burst of NO production in signaling response to insulin stimulation. These results were further confirmed by phosphatase activity assays. We investigated further the role ofNOas a regulator of insulin signaling by RNA interference that ablates endogenous eNOS expression in endothelial MS-1 cells. We have shown that eNOS-dependent NO production is essential for the activation of insulin signaling. Our findings demonstrate that NO mediates enhancement of insulin responsiveness via the inhibition of insulin receptor phosphatases. ? 2010 by The American Society for Biochemistry and Molecular Biology, Inc.
Other Subjects
Acidic conditions; Active site; Cysteine residues; Down-stream; Endothelial nitric-oxide synthase (eNOS); Function models; Insulin receptor substrate-1; Insulin receptors; Insulin sensitivity; Insulin signaling; Molecular basis; Phosphatase activity; Protein-tyrosine phosphatase; RNA interference; Sulfhydryl; Tyrosine phosphorylation; Amino acids; Endothelial cells; Nitric oxide; Phosphatases; Phosphorylation; Probes; Proteins; RNA; Self assembly; Signaling; Insulin; cysteine; endothelial nitric oxide synthase; insulin; insulin receptor; insulin receptor substrate 1; nitric oxide; non receptor protein tyrosine phosphatase 2; protein kinase B; protein tyrosine phosphatase; protein tyrosine phosphatase 1B; protein tyrosine phosphatase SHP 1; protein tyrosine phosphatase SHP 2; tyrosine; cysteine; insulin receptor substrate; nitric oxide donor; nitrogen; non receptor protein tyrosine phosphatase 2; protein kinase B; protein tyrosine phosphatase; protein tyrosine phosphatase 1B; protein tyrosine phosphatase SHP 1; protein tyrosine phosphatase SHP 2; small interfering RNA; tyrosine; animal cell; article; cell strain COS7; controlled study; endothelium cell; enzyme active site; enzyme activity; enzyme inactivation; enzyme inhibition; genetic transfection; hormonal regulation; human; human cell; insulin response; mouse; nitrosylation; nonhuman; priority journal; protein expression; protein phosphorylation; RNA interference; signal transduction; animal; cell strain COS1; Cercopithecus; genetics; metabolism; non insulin dependent diabetes mellitus; physiology; signal transduction; Animals; Cercopithecus aethiops; COS Cells; Cysteine; Diabetes Mellitus, Type 2; Insulin; Insulin Receptor Substrate Proteins; Nitric Oxide; Nitric Oxide Donors; Nitric Oxide Synthase Type III; Nitrogen; Protein Tyrosine Phosphatase, Non-Receptor Type 1; Protein Tyrosine Phosphatase, Non-Receptor Type 11; Protein Tyrosine Phosphatase, Non-Receptor Type 2; Protein Tyrosine Phosphatase, Non-Receptor Type 6; Protein Tyrosine Phosphatases; Proto-Oncogene Proteins c-akt; RNA, Small Interfering; Signal Transduction; Transfection; Tyrosine
Type
journal article
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