2023
The release of inhibition model reproduces kinetics and plasticity of neurotransmitter release in central synapses
Norman C, Krishnakumar S, Timofeeva Y, Volynski K. The release of inhibition model reproduces kinetics and plasticity of neurotransmitter release in central synapses. Communications Biology 2023, 6: 1091. PMID: 37891212, PMCID: PMC10611806, DOI: 10.1038/s42003-023-05445-2.Peer-Reviewed Original ResearchConceptsFusion clampSV exocytosisSynaptic vesiclesNeurotransmitter releaseSNARE complexSNARE proteinsSV fusionPhysiological timescalesSynaptotagmin-1Synergistic regulationMolecular biochemistryComplete assemblyPresynaptic proteinsSynaptotagmin-7Molecular architectureCalcium bindingExocytosisDual bindingProteinCentral synapsesBindingPlasticitySynaptotagminSnareVesiclesDirect determination of oligomeric organization of integral membrane proteins and lipids from intact customizable bilayer
Panda A, Giska F, Duncan A, Welch A, Brown C, McAllister R, Hariharan P, Goder J, Coleman J, Ramakrishnan S, Pincet F, Guan L, Krishnakumar S, Rothman J, Gupta K. Direct determination of oligomeric organization of integral membrane proteins and lipids from intact customizable bilayer. Nature Methods 2023, 20: 891-897. PMID: 37106230, PMCID: PMC10932606, DOI: 10.1038/s41592-023-01864-5.Peer-Reviewed Original ResearchConceptsIntegral membrane proteinsMembrane proteinsOligomeric organizationOligomeric stateNative mass spectrometry analysisFunctional oligomeric stateKey membrane componentMass spectrometry analysisNMS analysisTarget membraneLipid bindingMembrane componentsProteolipid vesiclesMembrane compositionLipid compositionSpectrometry analysisLipid membranesNeurotransmitter releaseProteinMembraneLipidsMembrane propertiesDirect determinationBilayersTransporters
2021
Vesicle capture by membrane‐bound Munc13‐1 requires self‐assembly into discrete clusters
Li F, Sundaram R, Gatta AT, Coleman J, Ramakrishnan S, Krishnakumar SS, Pincet F, Rothman JE. Vesicle capture by membrane‐bound Munc13‐1 requires self‐assembly into discrete clusters. FEBS Letters 2021, 595: 2185-2196. PMID: 34227103, DOI: 10.1002/1873-3468.14157.Peer-Reviewed Original ResearchConceptsMunc13-1Vesicle captureSpecific plasma membrane domainsStep-wise photobleachingC-domainMunc13-1 proteinPlasma membrane domainsSynaptic vesicle dockingC-terminal CVesicle dockingMembrane domainsTIRF microscopySoluble proteinVesicle membraneActive zoneMultiple copiesSynaptic vesiclesFunctional significanceSmall unilamellar vesiclesLipid bilayersVesiclesUnilamellar vesiclesProteinDiscrete clustersCopies
2020
Synergistic 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 roleFusionExocytosisMachineryProteinBindsMechanism
2019
Mechanisms 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 growthExocytosisGrowth
2017
Mutations 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 strategySnareFusionFragmentation
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
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