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 membraneSNAP25AssemblyBindingRecruits
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 insertion
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 controlPHluorinSyt1SYTRearrangements under confinement lead to increased binding energy of Synaptotagmin‐1 with anionic membranes in Mg2+ and Ca2+
Gruget C, Coleman J, Bello O, Krishnakumar SS, Perez E, Rothman JE, Pincet F, Donaldson SH. Rearrangements under confinement lead to increased binding energy of Synaptotagmin‐1 with anionic membranes in Mg2+ and Ca2+. FEBS Letters 2018, 592: 1497-1506. PMID: 29578584, DOI: 10.1002/1873-3468.13040.Peer-Reviewed Original ResearchMeSH KeywordsCalciumCell MembraneDose-Response Relationship, DrugMagnesiumProtein BindingSurface PropertiesSynaptotagmin IThermodynamics
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 synapses
2016
Ring-like oligomers of Synaptotagmins and related C2 domain proteins
Zanetti MN, Bello OD, Wang J, Coleman J, Cai Y, Sindelar CV, Rothman JE, Krishnakumar SS. Ring-like oligomers of Synaptotagmins and related C2 domain proteins. ELife 2016, 5: e17262. PMID: 27434670, PMCID: PMC4977156, DOI: 10.7554/elife.17262.Peer-Reviewed Original ResearchNanodisc-cell fusion: control of fusion pore nucleation and lifetimes by SNARE protein transmembrane domains
Wu Z, Auclair SM, Bello O, Vennekate W, Dudzinski NR, Krishnakumar SS, Karatekin E. Nanodisc-cell fusion: control of fusion pore nucleation and lifetimes by SNARE protein transmembrane domains. Scientific Reports 2016, 6: 27287. PMID: 27264104, PMCID: PMC4893671, DOI: 10.1038/srep27287.Peer-Reviewed Original ResearchConceptsFusion poreTransmembrane domainPore dynamicsProtein transmembrane domainNeurotransmitter-filled vesiclesT-SNAREsPlasma membraneRecycling kineticsPore lifetimePore currentsFlickering poresPore stabilityMultiple timesZipperingNanodiscsDomainProteinVesiclesMembraneCellsAssaysCognatesPore propertiesPores
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
2007
Membrane Topography of the Hydrophobic Anchor Sequence of Poliovirus 3A and 3AB Proteins and the Functional Effect of 3A/3AB Membrane Association upon RNA Replication †
Fujita K, Krishnakumar SS, Franco D, Paul AV, London E, Wimmer E. Membrane Topography of the Hydrophobic Anchor Sequence of Poliovirus 3A and 3AB Proteins and the Functional Effect of 3A/3AB Membrane Association upon RNA Replication †. Biochemistry 2007, 46: 5185-5199. PMID: 17417822, PMCID: PMC2519882, DOI: 10.1021/bi6024758.Peer-Reviewed Original ResearchConceptsModel membrane vesiclesAnchor sequenceHydrophobic anchor sequenceMembrane vesiclesViral protein 3ABFull-length proteinN-terminal boundaryTransmembrane topographyMembrane associationSuppressor mutationsTransmembrane segmentsProtein 3ABRNA polymeraseMembranous vesiclesC-terminusMembrane topographyCytoplasmic surfaceHost cellsRNA replicationPoliovirus RNAHeLa cellsSingle tryptophanProteinUridylylation reactionLipid bilayers