2017
Excess cholesterol inhibits glucose‐stimulated fusion pore dynamics in insulin exocytosis
Xu Y, Toomre DK, Bogan JS, Hao M. Excess cholesterol inhibits glucose‐stimulated fusion pore dynamics in insulin exocytosis. Journal Of Cellular And Molecular Medicine 2017, 21: 2950-2962. PMID: 28544529, PMCID: PMC5661106, DOI: 10.1111/jcmm.13207.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsCell Line, TumorCell MembraneCholesterolDiabetes Mellitus, Type 2DynaminsExocytosisGene Expression RegulationGlucoseHumansInsulinInsulin-Secreting CellsMembrane FusionMiceMicroscopy, FluorescenceModels, BiologicalPhosphatidylinositol 4,5-DiphosphateSecretory VesiclesSignal TransductionConceptsFusion pore dynamicsInsulin exocytosisFusion eventsPore dynamicsGlucose-triggered insulin secretionΒ-cellsFull fusionSingle granule levelTotal internal reflection fluorescence microscopySingle exocytic eventsReflection fluorescence microscopyImpairs β-cell functionExcess cholesterolGTPase dynaminExocytic eventsRole of cholesterolPlasma membranePancreatic β-cellsMolecular mechanismsInsulin granulesCompound exocytosisFusion kineticsΒ-cell dysfunctionExocytosisType 2 diabetes
2016
Optogenetic activation reveals distinct roles of PIP3 and Akt in adipocyte insulin action
Xu Y, Nan D, Fan J, Bogan JS, Toomre D. Optogenetic activation reveals distinct roles of PIP3 and Akt in adipocyte insulin action. Journal Of Cell Science 2016, 129: 2085-2095. PMID: 27076519, PMCID: PMC4878990, DOI: 10.1242/jcs.174805.Peer-Reviewed Original ResearchConceptsPI3KGLUT4 translocationDistinct rolesAkt-independent pathwayNew optogenetic toolsGlucose transporter 4Drug-mediated inhibitionTranslocation responseIntracellular vesiclesOverall insulin actionPlasma membraneInsulin actionN-terminusOptogenetic toolsInsulin stimulationTransporter 4Biochemical assaysAktTranslocationAdipose cellsVesiclesPathwayCIB1PIP3Cells
2011
Dual-mode of insulin action controls GLUT4 vesicle exocytosis
Xu Y, Rubin BR, Orme CM, Karpikov A, Yu C, Bogan JS, Toomre DK. Dual-mode of insulin action controls GLUT4 vesicle exocytosis. Journal Of Cell Biology 2011, 193: 643-653. PMID: 21555461, PMCID: PMC3166865, DOI: 10.1083/jcb.201008135.Peer-Reviewed Original ResearchMeSH Keywords3T3-L1 CellsAdipocytesAnimalsBiosensing TechniquesCarrier ProteinsExocytosisGlucose Transporter Type 4Green Fluorescent ProteinsInsulinIntracellular Signaling Peptides and ProteinsKineticsMembrane FusionMiceMicroscopy, FluorescenceMicroscopy, VideoPhospholipase DRecombinant Fusion ProteinsRNA InterferenceTransfectionTransport VesiclesVesicle-Associated Membrane Protein 2ConceptsGLUT4 storage vesiclesVesicle exocytosisInsulin-stimulated control cellsGLUT4 vesicle exocytosisPlasma membrane fusionNovel regulatory siteSingle vesicle exocytosisInsulin triggersVesicle trafficExocytic rateFusion poreSurface of adipocytesMembrane fusionRegulatory sitesPhospholipase DStorage vesiclesPore expansionExocytosisControl cellsAcute perturbationVesiclesInsulin actionVesicle characteristicsAdipocytesCells
2010
Deciphering subcellular processes in live imaging datasets via dynamic probabilistic networks
Letinic K, Sebastian R, Barthel A, Toomre D. Deciphering subcellular processes in live imaging datasets via dynamic probabilistic networks. Bioinformatics 2010, 26: 2029-2036. PMID: 20581401, PMCID: PMC2916721, DOI: 10.1093/bioinformatics/btq331.Peer-Reviewed Original ResearchConceptsTotal internal reflection fluorescence microscopyCellular statesDistinct cellular statesSpatial-temporal regulationNon-polarized cellsComplex intracellular processesReflection fluorescence microscopyLive cell imaging dataOrganelle behaviorGLUT4 vesiclesProtein complexesCellular processesSpatial regulationDevelopmental processesBiological processesSubcellular processesCell imaging dataCell polarizationLiving cellsIntracellular processesBlood glucose homeostasisFluorescence microscopyExocytosisCell imagingStatic snapshots