2021
Symmetrical arrangement of proteins under release-ready vesicles in presynaptic terminals
Radhakrishnan A, Li X, Grushin K, Krishnakumar SS, Liu J, Rothman JE. Symmetrical arrangement of proteins under release-ready vesicles in presynaptic terminals. Proceedings Of The National Academy Of Sciences Of The United States Of America 2021, 118: e2024029118. PMID: 33468631, PMCID: PMC7865176, DOI: 10.1073/pnas.2024029118.Peer-Reviewed Original ResearchConceptsPlasma membraneSynaptic vesiclesSV fusionRelease-ready vesiclesFusion machinerySingle SNAREpinSV releaseExocytosis machineryMolecular eventsNative conditionsProtein componentsCultured hippocampal neuronsPriming reactionPresynaptic CaVesiclesFundamental processesProtein densityProtein massRelease of neurotransmittersNeurotransmitter releaseMachineryPresynaptic terminalsReleasable poolHippocampal neuronsVariable number
2020
Munc13 binds and recruits SNAP25 to chaperone SNARE complex assembly
Sundaram R, Jin H, Li F, Shu T, Coleman J, Yang J, Pincet F, Zhang Y, Rothman JE, Krishnakumar SS. Munc13 binds and recruits SNAP25 to chaperone SNARE complex assembly. FEBS Letters 2020, 595: 297-309. PMID: 33222163, PMCID: PMC8068094, DOI: 10.1002/1873-3468.14006.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsBinding SitesCloning, MolecularEscherichia coliGene ExpressionGenetic VectorsLipid BilayersLiposomesMiceModels, MolecularNerve Tissue ProteinsOptical TweezersPhosphatidylcholinesPhosphatidylethanolaminesPhosphatidylserinesPolyethylene GlycolsProtein BindingProtein Conformation, alpha-HelicalProtein Conformation, beta-StrandProtein Interaction Domains and MotifsRecombinant Fusion ProteinsSynaptosomal-Associated Protein 25Syntaxin 1Vesicle-Associated Membrane Protein 2ConceptsSNARE complex assemblyComplex assemblyMunc13-1 MUN domainDetailed structure-function analysisSNARE protein VAMP2Syntaxin 1/Structure-function analysisSynaptic vesicle fusionOptical tweezers studiesSNARE assemblySNARE motifMUN domainMunc18-1Syntaxin-1Munc13-1FRET spectroscopyLinker regionVesicle fusionDirect bindingPhospholipid bilayersPresynaptic membraneSNAP25AssemblyBindingRecruitsSynergistic roles of Synaptotagmin-1 and complexin in calcium-regulated neuronal exocytosis
Ramakrishnan S, Bera M, Coleman J, Rothman JE, Krishnakumar SS. Synergistic roles of Synaptotagmin-1 and complexin in calcium-regulated neuronal exocytosis. ELife 2020, 9: e54506. PMID: 32401194, PMCID: PMC7220375, DOI: 10.7554/elife.54506.Peer-Reviewed Original ResearchConceptsSynaptotagmin-1Vesicular fusion machinerySingle-vesicle fusionFusion of vesiclesSNARE complexFusion machineryNeuronal exocytosisOligomer bindsRegulatory proteinsVesicle fusionSNAREpinsSynchronous fusionSynaptic vesiclesNovel mechanismVesiclesComplexinKinetic delayPrimary interfaceSynergistic roleFusionExocytosisMachineryProteinBindsMechanismSynaptotagmin 1 oligomers clamp and regulate different modes of neurotransmitter release
Tagliatti E, Bello OD, Mendonça PRF, Kotzadimitriou D, Nicholson E, Coleman J, Timofeeva Y, Rothman JE, Krishnakumar SS, Volynski KE. Synaptotagmin 1 oligomers clamp and regulate different modes of neurotransmitter release. Proceedings Of The National Academy Of Sciences Of The United States Of America 2020, 117: 3819-3827. PMID: 32015138, PMCID: PMC7035618, DOI: 10.1073/pnas.1920403117.Peer-Reviewed Original Research
2019
Structural basis for the clamping and Ca2+ activation of SNARE-mediated fusion by synaptotagmin
Grushin K, Wang J, Coleman J, Rothman JE, Sindelar CV, Krishnakumar SS. Structural basis for the clamping and Ca2+ activation of SNARE-mediated fusion by synaptotagmin. Nature Communications 2019, 10: 2413. PMID: 31160571, PMCID: PMC6546687, DOI: 10.1038/s41467-019-10391-x.Peer-Reviewed Original ResearchConceptsCryo-electron microscopy structureActivation of SNAREsDependent membrane interactionsAnionic lipid headgroupsFusion clampActivator functionSNARE bundleSNARE proteinsMicroscopy structureC2B domainStructural basisSynaptotagmin-1SNAREpinsAliphatic loopsMembrane interactionsComplete assemblyLipid headgroupsLipid membranesNeurotransmitter releaseMembraneKey determinantSynaptotagminSyt1Calcium influxPartial insertionMechanisms of Neurological Dysfunction in GOSR2 Progressive Myoclonus Epilepsy, a Golgi SNAREopathy
Jepson JEC, Praschberger R, Krishnakumar SS. Mechanisms of Neurological Dysfunction in GOSR2 Progressive Myoclonus Epilepsy, a Golgi SNAREopathy. Neuroscience 2019, 420: 41-49. PMID: 30954670, DOI: 10.1016/j.neuroscience.2019.03.057.Peer-Reviewed Original ResearchConceptsEndoplasmic reticulumSNARE proteinsProgressive myoclonus epilepsySecretory trafficking pathwaysCis-Golgi membranesMis-sense mutationsTransport vesiclesGolgi transportTrafficking pathwaysVesicles budSecretory pathwaySuccessive fusion eventsTarget membraneFusion eventsEssential functionsDevelopmental defectsMolecular mechanismsMyoclonus epilepsyProteinFusion stepSevere neurological disordersMutationsMembranePathwayInitial stepSymmetrical organization of proteins under docked synaptic vesicles
Li X, Radhakrishnan A, Grushin K, Kasula R, Chaudhuri A, Gomathinayagam S, Krishnakumar SS, Liu J, Rothman JE. Symmetrical organization of proteins under docked synaptic vesicles. FEBS Letters 2019, 593: 144-153. PMID: 30561792, PMCID: PMC6353562, DOI: 10.1002/1873-3468.13316.Peer-Reviewed Original ResearchConceptsCryo-electron tomography analysisSymmetrical organizationCalcium-regulated exocytosisMunc18 proteinsProtein machineryFusion machinerySingle SNAREpinCircular oligomersMutational analysisRadial positioningSynaptic vesiclesRelease machineryMachinerySynaptotagminProteinRing hypothesisVesiclesObserved arrangementUnderlying mechanismSNAREpinsComplexinNerve growthExocytosisGrowthSynaptotagmin oligomers are necessary and can be sufficient to form a Ca2+‐sensitive fusion clamp
Ramakrishnan S, Bera M, Coleman J, Krishnakumar SS, Pincet F, Rothman JE. Synaptotagmin oligomers are necessary and can be sufficient to form a Ca2+‐sensitive fusion clamp. FEBS Letters 2019, 593: 154-162. PMID: 30570144, PMCID: PMC6349546, DOI: 10.1002/1873-3468.13317.Peer-Reviewed Original Research
2018
Synaptotagmin oligomerization is essential for calcium control of regulated exocytosis
Bello OD, Jouannot O, Chaudhuri A, Stroeva E, Coleman J, Volynski KE, Rothman JE, Krishnakumar SS. Synaptotagmin oligomerization is essential for calcium control of regulated exocytosis. Proceedings Of The National Academy Of Sciences Of The United States Of America 2018, 115: e7624-e7631. PMID: 30038018, PMCID: PMC6094142, DOI: 10.1073/pnas.1808792115.Peer-Reviewed Original ResearchConceptsRegulated exocytosisFusion machineryC2 domain proteinsCore fusion machinerySingle vesicle exocytosisConstitutive exocytosisPrincipal CaVesicular releaseMolecular mechanismsSensitive oligomersExocytosisPheochromocytoma cellsSelective disruptionSpontaneous fusionCritical roleMachineryOligomerizationDirect activationCentral componentStructural featuresConsiderable insightCalcium controlPHluorinSyt1SYTSynergistic control of neurotransmitter release by different members of the synaptotagmin family
Volynski KE, Krishnakumar SS. Synergistic control of neurotransmitter release by different members of the synaptotagmin family. Current Opinion In Neurobiology 2018, 51: 154-162. PMID: 29886350, DOI: 10.1016/j.conb.2018.05.006.Peer-Reviewed Original ResearchPRRT2 Regulates Synaptic Fusion by Directly Modulating SNARE Complex Assembly
Coleman J, Jouannot O, Ramakrishnan SK, Zanetti MN, Wang J, Salpietro V, Houlden H, Rothman JE, Krishnakumar SS. PRRT2 Regulates Synaptic Fusion by Directly Modulating SNARE Complex Assembly. Cell Reports 2018, 22: 820-831. PMID: 29346777, PMCID: PMC5792450, DOI: 10.1016/j.celrep.2017.12.056.Peer-Reviewed Original ResearchConceptsProline-rich transmembrane protein 2SNARE complex assemblyComplex assemblyTrans-SNARE complex assemblyTerminal proline-rich domainSynaptic SNARE proteinsProline-rich domainParoxysmal neurological disordersSynaptic vesicle primingLive-cell imagingTransmembrane protein 2Synaptic fusionSNARE proteinsVesicle primingSingle exocytotic eventsBiophysical analysisFusion assaysMolecular mechanismsFunction mutationsPhysiological roleExocytotic eventsPre-synaptic terminalsPC12 cellsProtein 2Single vesicles
2017
Otoferlin acts as a Ca2+ sensor for vesicle fusion and vesicle pool replenishment at auditory hair cell ribbon synapses
Michalski N, Goutman JD, Auclair SM, de Monvel J, Tertrais M, Emptoz A, Parrin A, Nouaille S, Guillon M, Sachse M, Ciric D, Bahloul A, Hardelin JP, Sutton RB, Avan P, Krishnakumar SS, Rothman JE, Dulon D, Safieddine S, Petit C. Otoferlin acts as a Ca2+ sensor for vesicle fusion and vesicle pool replenishment at auditory hair cell ribbon synapses. ELife 2017, 6: e31013. PMID: 29111973, PMCID: PMC5700815, DOI: 10.7554/elife.31013.Peer-Reviewed Original ResearchConceptsVesicle fusionVesicle pool replenishmentIHC active zonesInner hair cellsPresynaptic plasma membraneSynaptic vesicle cycleMembrane capacitance measurementsRole of otoferlinAuditory brainstem response wavesTransmembrane proteinVesicle cycleSynaptic exocytosisPlasma membraneVoltage-gated CaHair cell ribbonC-domainSynaptic vesiclesOtoferlinSynaptic CaSensory cellsSynapse structureIntracellular CaNeurotransmitter releaseMutant miceRibbon synapsesHypothesis – buttressed rings assemble, clamp, and release SNAREpins for synaptic transmission
Rothman JE, Krishnakumar SS, Grushin K, Pincet F. Hypothesis – buttressed rings assemble, clamp, and release SNAREpins for synaptic transmission. FEBS Letters 2017, 591: 3459-3480. PMID: 28983915, PMCID: PMC5698743, DOI: 10.1002/1873-3468.12874.Peer-Reviewed Original ResearchTwo Disease-Causing SNAP-25B Mutations Selectively Impair SNARE C-terminal Assembly
Rebane AA, Wang B, Ma L, Qu H, Coleman J, Krishnakumar S, Rothman JE, Zhang Y. Two Disease-Causing SNAP-25B Mutations Selectively Impair SNARE C-terminal Assembly. Journal Of Molecular Biology 2017, 430: 479-490. PMID: 29056461, PMCID: PMC5805579, DOI: 10.1016/j.jmb.2017.10.012.Peer-Reviewed Original ResearchConceptsSoluble N-ethylmaleimide-sensitive factor attachment receptorSNARE assemblySynaptic exocytosisMembrane fusionSingle-molecule optical tweezersT-SNARE complexVesicle-associated SNAREsTarget plasma membraneC-terminal assemblyFour-helix bundleC-terminal regionSNARE complexPlasma membraneMolecular mechanismsZipperingMutationsNumerous diseasesAssembly energyNeurotransmitter releaseExocytosisAttachment receptorAssemblyNeurological disordersOptical tweezersComplexesMutations in Membrin/GOSR2 Reveal Stringent Secretory Pathway Demands of Dendritic Growth and Synaptic Integrity
Praschberger R, Lowe SA, Malintan NT, Giachello CNG, Patel N, Houlden H, Kullmann DM, Baines RA, Usowicz MM, Krishnakumar SS, Hodge JJL, Rothman JE, Jepson JEC. Mutations in Membrin/GOSR2 Reveal Stringent Secretory Pathway Demands of Dendritic Growth and Synaptic Integrity. Cell Reports 2017, 21: 97-109. PMID: 28978487, PMCID: PMC5640804, DOI: 10.1016/j.celrep.2017.09.004.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsDendritesDrosophila melanogasterFemaleFibroblastsGene ExpressionGenetic Association StudiesGolgi ApparatusHumansMaleMembrane FusionMutationMyoclonic Epilepsies, ProgressivePhenotypePrimary Cell CultureQb-SNARE ProteinsRecombinant ProteinsSaccharomyces cerevisiaeSaccharomyces cerevisiae ProteinsSecretory PathwaySynapsesYoung AdultConceptsMembrane fusionGolgi membrane fusionProgressive myoclonus epilepsyGenotype-phenotype relationshipsPresynaptic cytoskeletonEssential proteinsDrosophila modelMembrinMutationsPathogenic mutationsSynaptic functionProteinMyoclonus epilepsyExplanatory basisCytoskeletonGrowthSynaptic integrityPathway deficitsNervous systemMulti-layered strategySnareFusionFragmentationHomozygous mutations in VAMP1 cause a presynaptic congenital myasthenic syndrome
Salpietro V, Lin W, Delle Vedove A, Storbeck M, Liu Y, Efthymiou S, Manole A, Wiethoff S, Ye Q, Saggar A, McElreavey K, Krishnakumar SS, Group S, Pitt M, Bello OD, Rothman JE, Basel‐Vanagaite L, Hubshman MW, Aharoni S, Manzur AY, Wirth B, Houlden H. Homozygous mutations in VAMP1 cause a presynaptic congenital myasthenic syndrome. Annals Of Neurology 2017, 81: 597-603. PMID: 28253535, PMCID: PMC5413866, DOI: 10.1002/ana.24905.Peer-Reviewed Original ResearchConceptsPresynaptic congenital myasthenic syndromeCongenital myasthenic syndromePresynaptic impairmentMyasthenic syndromeLow compound muscle action potentialsNeuromuscular junctionCompound muscle action potentialPresynaptic neuromuscular junctionHomozygous mutationMuscle action potentialsAnn NeurolNMJ transmissionElectrodiagnostic examinationNeurophysiological featuresAction potentialsLew/Homozygous variantMRNA levelsSyndromeWhole exomeImpairmentVAMP1Kuwaiti familyNonsense mutationMutationsKv1.1 channelopathy abolishes presynaptic spike width modulation by subthreshold somatic depolarization
Vivekananda U, Novak P, Bello OD, Korchev YE, Krishnakumar SS, Volynski KE, Kullmann DM. Kv1.1 channelopathy abolishes presynaptic spike width modulation by subthreshold somatic depolarization. Proceedings Of The National Academy Of Sciences Of The United States Of America 2017, 114: 2395-2400. PMID: 28193892, PMCID: PMC5338558, DOI: 10.1073/pnas.1608763114.Peer-Reviewed Original ResearchConceptsSomatic depolarizationPotassium channelsAction potentialsPresynaptic potassium channelsPrimary hippocampal culturesSubthreshold membrane potential fluctuationsHeterozygous mouse modelEpisodic ataxia type 1Distinct potassium channelsSubthreshold modulationAxon transectionSmall boutonsCalcium influxHippocampal culturesMouse modelSynaptic boutonsKv1.1 subunitsMembrane potential fluctuationsNeurotransmitter releaseIntact axonsType 1Genetic deletionAtaxia type 1Further prolongationPresynaptic spikes
2015
Re-visiting the trans insertion model for complexin clamping
Krishnakumar SS, Li F, Coleman J, Schauder CM, Kümmel D, Pincet F, Rothman JE, Reinisch KM. Re-visiting the trans insertion model for complexin clamping. ELife 2015, 4: e04463. PMID: 25831964, PMCID: PMC4384536, DOI: 10.7554/elife.04463.Peer-Reviewed Original ResearchAdaptor Proteins, Vesicular TransportAlgorithmsAnimalsCalorimetryCircular DichroismEntropyFluorescence Resonance Energy TransferHumansKineticsMembrane FusionModels, NeurologicalMutationNerve Tissue ProteinsNeuronsProtein BindingSignal TransductionSNARE ProteinsSynaptic TransmissionSynaptotagminsVesicle-Associated Membrane Protein 2
2013
Conformational Dynamics of Calcium-Triggered Activation of Fusion by Synaptotagmin
Krishnakumar SS, Kümmel D, Jones SJ, Radoff DT, Reinisch KM, Rothman JE. Conformational Dynamics of Calcium-Triggered Activation of Fusion by Synaptotagmin. Biophysical Journal 2013, 105: 2507-2516. PMID: 24314081, PMCID: PMC3853086, DOI: 10.1016/j.bpj.2013.10.029.Peer-Reviewed Original Research
2011
A conformational switch in complexin is required for synaptotagmin to trigger synaptic fusion
Krishnakumar SS, Radoff DT, Kümmel D, Giraudo CG, Li F, Khandan L, Baguley SW, Coleman J, Reinisch KM, Pincet F, Rothman JE. A conformational switch in complexin is required for synaptotagmin to trigger synaptic fusion. Nature Structural & Molecular Biology 2011, 18: 934-940. PMID: 21785412, PMCID: PMC3668341, DOI: 10.1038/nsmb.2103.Peer-Reviewed Original ResearchMeSH KeywordsAdaptor Proteins, Vesicular TransportAmino Acid SequenceAnimalsBinding SitesCrystallography, X-RayHumansMembrane FusionModels, MolecularMolecular Sequence DataMutagenesis, Site-DirectedNerve Tissue ProteinsProtein Structure, TertiaryRatsSynaptosomal-Associated Protein 25SynaptotagminsSyntaxin 1Vesicle-Associated Membrane Protein 2