title: Nitric oxide attenuates signal transduction: possible role in dissociating caveolin-1 scaffold.
abstract: Caveolae harbor different serpentine receptors, intracellular components of signaling cascades, and certain enzymes, including endothelial nitric oxide synthase (eNOS). The regulation of eNOS activity by Ca(2+)/calmodulin and caveolin has been described. We have previously demonstrated that nitric oxide (NO) can modulate signaling initiated via receptors localized to caveolae. In the present study, we show that NO donors induced an increase in the monomeric form of this scaffolding protein in cultured endothelial cells, the effect mimicked by 8-bromo cGMP. Proximity imaging of endothelial cells transfected with the thermotolerant green fluorescent protein-caveolin-1 construct demonstrated that sodium nitroprusside resulted in the increased fluorescence ratio of 410:470 nm, consistent with the distancing of fluorescently tagged caveolin-1. Pulse labeling of endothelial cells with cholera toxin B subunit indicated that sodium nitroprusside reversibly decreased its binding. Signaling via G protein-coupled receptors resident to caveolae was inhibited by pretreatment with NO donor. The data demonstrate that NO modulation of cell signaling is accomplished in part by regulating the state of caveolin-1 oligomerization. NO-induced attenuation of signaling involves reversible dissociation of caveolin scaffold, thus providing both spatial and temporal modulation of signal transduction.
authors.affiliation: Department of Medicine, State University of New York, Stony Brook, NY11794-8152, USA.
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.forename: S
authors.initials: S
authors.lastname: Brodsky
authors.forename: M
authors.initials: M
authors.lastname: Basco
authors.forename: V
authors.initials: V
authors.lastname: Romanov
authors.forename: D A
authors.initials: DA
authors.lastname: De Angelis
authors.forename: M S
authors.initials: MS
authors.lastname: Goligorsky
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D021941:Caveolae / Q000187:drug effects / Q000378:metabolism; D051242:Caveolin 1; D022461:Caveolins / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D002499:Centrifugation, Density Gradient; D002772:Cholera Toxin / Q000494:pharmacology; D019332:Endothelin-1 / Q000378:metabolism / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D049452:Green Fluorescent Proteins; D006801:Humans; D017736:Ion-Selective Electrodes; D008164:Luminescent Proteins / Q000235:genetics; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism* / Q000494:pharmacology; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III; D009599:Nitroprusside / Q000494:pharmacology; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: C495540:CAV1 protein, human; C495537:Cav1 protein, rat; D051242:Caveolin 1; D022461:Caveolins; D019332:Endothelin-1; D004791:Enzyme Inhibitors; D008164:Luminescent Proteins; D020030:Nitric Oxide Donors; D011993:Recombinant Fusion Proteins; D014665:Vasodilator Agents; D049452:Green Fluorescent Proteins; D009599:Nitroprusside; D009569:Nitric Oxide; D002772:Cholera Toxin; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D002118:Calcium