2025
1824-P: Bioenergetic Advantage of Pyruvate Kinase Overcomes Mitochondrial OXPHOS in Beta-Cells to Initiate Insulin Secretion
RUZ-MALDONADO I, CARDONE R, MERRINS M, KIBBEY R. 1824-P: Bioenergetic Advantage of Pyruvate Kinase Overcomes Mitochondrial OXPHOS in Beta-Cells to Initiate Insulin Secretion. Diabetes 2025, 74 DOI: 10.2337/db25-1824-p.Peer-Reviewed Original ResearchPyruvate kinaseATP/ADP ratioMitochondrial OXPHOSHuman isletsBeta-cellsIntact miceOxygen consumption rateKATP channel closureInsulin secretionMitochondrial membrane potentialPlasma membrane depolarizationDose-dependent mannerIntramitochondrial ADPADP availabilityHyperpolarized mitochondriaInitial insulin secretionKATP channelsMitochondrial hyperpolarizationOXPHOS inhibitionINS-1Pyruvate metabolismETC complexesMembrane depolarizationATP synthesisOXPHOS1840-P: Pyruvate Kinase Bioenergetically Restricts OXPHOS in Beta Cells and Myotubules by Inducing Mitochondrial Membrane Hyperpolarization
DAVIDSON E, KIBBEY R. 1840-P: Pyruvate Kinase Bioenergetically Restricts OXPHOS in Beta Cells and Myotubules by Inducing Mitochondrial Membrane Hyperpolarization. Diabetes 2025, 74 DOI: 10.2337/db25-1840-p.Peer-Reviewed Original ResearchMitochondrial membrane potentialPyruvate kinaseHyperpolarization of mitochondrial membrane potentialRespiratory suppressionMitochondrial membrane potential differenceMitochondrial membrane hyperpolarizationCytosolic ATP/ADP ratioComplex V activityDigestive and Kidney DiseasesINS-1ATP hydrolysisATP synthesisPhosphoenolpyruvateMembrane hyperpolarizationPK substratesBlocking electron transportOXPHOSKidney diseaseATP/ADP ratioBeta cellsHyperpolarizationMembrane potentialPK activityState 3Oligos
2024
1734-P: ADP Privation of Human Beta-Cell Mitochondria by Pyruvate Kinase
RUZ-MALDONADO I, CARDONE R, KIBBEY R. 1734-P: ADP Privation of Human Beta-Cell Mitochondria by Pyruvate Kinase. Diabetes 2024, 73 DOI: 10.2337/db24-1734-p.Peer-Reviewed Original ResearchPyruvate kinaseBeta-cell mitochondriaInhibition of OxPhosBeta-cellsHuman beta-cellsModulation of enzymesIntramitochondrial ADPPhosphoenolpyruvate inhibitionADP availabilityADP/ATP exchangeKATP channelsPhosphoenolpyruvate metabolismOxidative phosphorylationPhosphoenolpyruvateMitochondrial functionOXPHOSSubstrate transportComplex IATP/ADP ratioHuman isletsMitochondrial couplingOxygen consumption ratePyruvateMitochondriaDose-dependent mannerGlucose Regulation of β-Cell KATP Channels: It Is Time for a New Model!
Merrins M, Kibbey R. Glucose Regulation of β-Cell KATP Channels: It Is Time for a New Model! Diabetes 2024, 73: 856-863. PMID: 38768366, PMCID: PMC11109790, DOI: 10.2337/dbi23-0032.Peer-Reviewed Original ResearchConceptsB-cell metabolismInsulin secretionEfficiency of mitochondrial ATP productionModel of glucose-stimulated insulin secretionGlucose-stimulated insulin secretionMitochondrial ATP productionNADPH productionGenetic evidenceInitial insulin secretionATP productionGlycolytic enzymesOXPHOSPyruvate kinaseATP/ADP ratioHealthy B cellsKATP channel closureB cellsDiabetes pathophysiologyGlycolysisStoichiometric yieldKATP channelsBioenergeticsATP/ADPMembrane depolarizationMetabolism
2022
β-cell deletion of the PKm1 and PKm2 isoforms of pyruvate kinase in mice reveals their essential role as nutrient sensors for the KATP channel
Foster HR, Ho T, Potapenko E, Sdao SM, Huang SM, Lewandowski SL, VanDeusen HR, Davidson SM, Cardone RL, Prentki M, Kibbey RG, Merrins MJ. β-cell deletion of the PKm1 and PKm2 isoforms of pyruvate kinase in mice reveals their essential role as nutrient sensors for the KATP channel. ELife 2022, 11: e79422. PMID: 35997256, PMCID: PMC9444242, DOI: 10.7554/elife.79422.Peer-Reviewed Original ResearchConceptsPyruvate kinaseATP/ADPCytosolic ATP/ADPAmino acidsPKM2 isoformPK isoformsPlasma membraneNutrient sensorNutrient responsesPEP carboxykinasePKM1Mitochondrial sourcesPKM2Channel closureEssential roleInsulin secretionDifferential responsePK activityKinaseMembrane depolarizationIsoformsDeletionATPKey roleADP316-OR: Genetic Deletion of Beta-Cell Pkm1, Pkm2, and Pck2 Identifies PEP as an Essential Signal for Compartmentalized KATP Closure and Cycling of the Insulin Secretory Pathway
FOSTER H, HO T, POTAPENKO E, CARDONE R, KIBBEY R, MERRINS M. 316-OR: Genetic Deletion of Beta-Cell Pkm1, Pkm2, and Pck2 Identifies PEP as an Essential Signal for Compartmentalized KATP Closure and Cycling of the Insulin Secretory Pathway. Diabetes 2022, 71 DOI: 10.2337/db22-316-or.Peer-Reviewed Original ResearchΒ-cell-specific deletionΒ-cell metabolismStrong genetic evidenceSense nutrientsNutrient-stimulated insulin secretionAppropriate insulin secretionSecretory pathwayPKM2 isoformGenetic evidenceInsulin secretory pathwayPKM isoformsPKM1PCK2Essential signalAmino acidsPKM2Pyruvate kinaseADP generationΒ-cell responseInitiation of Ca2Genetic deletionIsoform expressionΒ-cellsDeletionInsulin secretion
2020
Pyruvate Kinase Controls Signal Strength in the Insulin Secretory Pathway
Lewandowski SL, Cardone RL, Foster HR, Ho T, Potapenko E, Poudel C, VanDeusen HR, Sdao SM, Alves TC, Zhao X, Capozzi ME, de Souza AH, Jahan I, Thomas CJ, Nunemaker CS, Davis DB, Campbell JE, Kibbey RG, Merrins MJ. Pyruvate Kinase Controls Signal Strength in the Insulin Secretory Pathway. Cell Metabolism 2020, 32: 736-750.e5. PMID: 33147484, PMCID: PMC7685238, DOI: 10.1016/j.cmet.2020.10.007.Peer-Reviewed Original ResearchConceptsPyruvate kinaseATP/ADPΒ-cell metabolismAppropriate insulin secretionPotential therapeutic routeSecretory pathwayMitochondrial fuelsPancreatic β-cellsInsulin secretory pathwayOxidative phosphorylationCell metabolismNutrient metabolismPhosphoenolpyruvateCell sensingPK activatorΒ-cellsCell functionInsulin secretionPK activityOxidative functionMembrane depolarizationMitochondriaPK activationΒ-cell functionADP
2019
Distinct Hepatic PKA and CDK Signaling Pathways Control Activity-Independent Pyruvate Kinase Phosphorylation and Hepatic Glucose Production
Gassaway BM, Cardone RL, Padyana AK, Petersen MC, Judd ET, Hayes S, Tong S, Barber KW, Apostolidi M, Abulizi A, Sheetz JB, Kshitiz, Aerni HR, Gross S, Kung C, Samuel VT, Shulman GI, Kibbey RG, Rinehart J. Distinct Hepatic PKA and CDK Signaling Pathways Control Activity-Independent Pyruvate Kinase Phosphorylation and Hepatic Glucose Production. Cell Reports 2019, 29: 3394-3404.e9. PMID: 31825824, PMCID: PMC6951436, DOI: 10.1016/j.celrep.2019.11.009.Peer-Reviewed Original ResearchConceptsCyclin-dependent kinasesMetabolic control pointPhosphorylation sitesNuclear retentionCDK activityPKL activityDays high-fat dietKinase phosphorylationImportant enzymePyruvate kinaseHigh-fat dietS113KinaseEnzyme kineticsPhosphorylationAdditional control pointsRegulationGlucose productionHepatic glucose productionInsulin resistanceGlycolysisEnzymePKAPathwayActivity
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