2023
Synaptophysin chaperones the assembly of 12 SNAREpins under each ready-release vesicle
Bera M, Radhakrishnan A, Coleman J, Sundaram R, Ramakrishnan S, Pincet F, Rothman J. Synaptophysin chaperones the assembly of 12 SNAREpins under each ready-release vesicle. Proceedings Of The National Academy Of Sciences Of The United States Of America 2023, 120: e2311484120. PMID: 37903271, PMCID: PMC10636311, DOI: 10.1073/pnas.2311484120.Peer-Reviewed Original ResearchConceptsSpecific molecular functionsSynaptic vesicle protein synaptophysinTarget membrane bilayerSensor synaptotagminSNARE proteinsMolecular functionsMembrane proteinsSNAREpinsReceptor vesiclesSingle-molecule measurementsGene knockoutMembrane bilayerLipid bilayersProtein synaptophysinVesiclesDetergent extractsHexamer structureSYPMechanism of actionProteinAssemblyChaperonesSynaptotagminExocytosisBilayersRoles for diacylglycerol in synaptic vesicle priming and release revealed by complete reconstitution of core protein machinery
Sundaram R, Chatterjee A, Bera M, Grushin K, Panda A, Li F, Coleman J, Lee S, Ramakrishnan S, Ernst A, Gupta K, Rothman J, Krishnakumar S. Roles for diacylglycerol in synaptic vesicle priming and release revealed by complete reconstitution of core protein machinery. Proceedings Of The National Academy Of Sciences Of The United States Of America 2023, 120: e2309516120. PMID: 37590407, PMCID: PMC10450444, DOI: 10.1073/pnas.2309516120.Peer-Reviewed Original ResearchConceptsCore protein machineryRelease-ready vesiclesSynaptic vesicle primingVesicle primingProtein machinerySingle-molecule imagingSNAREpin assemblyFunctional intermediatesFunctional reconstitutionMunc13DiacylglycerolCoordinated actionMunc18VesiclesMachineryComplete reconstitutionNew roleSelective effectDetailed characterizationChaperonesRate of caReconstitutionVAMP2ComplexinMutations
2022
Native Planar Asymmetric Suspended Membrane for Single‐Molecule Investigations: Plasma Membrane on a Chip (Small 51/2022)
Sundaram R, Bera M, Coleman J, Weerakkody J, Krishnakumar S, Ramakrishnan S. Native Planar Asymmetric Suspended Membrane for Single‐Molecule Investigations: Plasma Membrane on a Chip (Small 51/2022). Small 2022, 18 DOI: 10.1002/smll.202270277.Peer-Reviewed Original ResearchGiant plasma membrane vesiclesTotal internal reflection fluorescence microscopyMembrane protein assemblyPlasma membrane vesiclesReflection fluorescence microscopyDifferent cell typesSingle-molecule investigationsProtein functionProtein assembliesInner leafletPlasma membraneMembrane vesiclesCell typesLipid architectureFluorescence microscopyLipid membranesMolecule investigationsMembraneSilicon-based platformVesiclesAssemblyCellsBilayersLeafletsMolecular determinants of complexin clamping and activation function
Bera M, Ramakrishnan S, Coleman J, Krishnakumar SS, Rothman JE. Molecular determinants of complexin clamping and activation function. ELife 2022, 11: e71938. PMID: 35442188, PMCID: PMC9020821, DOI: 10.7554/elife.71938.Peer-Reviewed Original ResearchConceptsSynaptotagmin-1Single-vesicle fusionAccessory helixFusion clampHelical domainMolecular detailsComplexinMutational analysisVesicle releaseFusion kineticsMolecular determinantsSpecific interactionsInhibitory functionProbability of fusionRapid CaSNAREpinsAssembly processFusionClamping functionDomainHelixVesiclesFunctionMembraneInteraction
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 clustersCopiesNascent fusion pore opening monitored at single-SNAREpin resolution
Heo P, Coleman J, Fleury JB, Rothman JE, Pincet F. Nascent fusion pore opening monitored at single-SNAREpin resolution. Proceedings Of The National Academy Of Sciences Of The United States Of America 2021, 118: e2024922118. PMID: 33495324, PMCID: PMC7865171, DOI: 10.1073/pnas.2024922118.Peer-Reviewed Original ResearchConceptsFusion poreFusion pore openingTransient fusion poresSingle fusion eventFast neurotransmitter releaseSingle SNAREpinAsymmetric lipid bilayerProtein complexesSNAREpinsTarget membraneFusion eventsCellular traffickingVesicle fusionSmall vesiclesIon channelsLipid bilayersCargo transportKey eventsEnergy landscapePore openingNeurotransmitter releaseDiscrete sizesVesiclesSynaptic transmissionCargo release
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
Synaptotagmin 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
High-Throughput Monitoring of Single Vesicle Fusion Using Freestanding Membranes and Automated Analysis
Ramakrishnan S, Gohlke A, Li F, Coleman J, Xu W, Rothman JE, Pincet F. High-Throughput Monitoring of Single Vesicle Fusion Using Freestanding Membranes and Automated Analysis. Langmuir 2018, 34: 5849-5859. PMID: 29694054, DOI: 10.1021/acs.langmuir.8b00116.Peer-Reviewed Original ResearchConceptsMembrane fusionFusion eventsSoluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteinsSNARE-dependent membrane fusionIndividual vesicle fusion eventsFactor attachment protein receptor proteinsN-ethylmaleimide-sensitive factor attachment protein receptor proteinsT-SNARE proteinsSingle-vesicle fusionProtein receptor proteinsVesicle fusion eventsMobility of proteinsVesicle dockingContent releaseVesicle fusionHigh-throughput monitoringPlanar membranesReceptor proteinLipid mixingProteinLipid bilayersVesiclesCorrect reconstitutionMembraneAqueous compartment
2010
Phosphatidylinositol 4-Phosphate Controls Both Membrane Recruitment and a Regulatory Switch of the Rab GEF Sec2p
Mizuno-Yamasaki E, Medkova M, Coleman J, Novick P. Phosphatidylinositol 4-Phosphate Controls Both Membrane Recruitment and a Regulatory Switch of the Rab GEF Sec2p. Developmental Cell 2010, 18: 828-840. PMID: 20493815, PMCID: PMC2877039, DOI: 10.1016/j.devcel.2010.03.016.Peer-Reviewed Original ResearchConceptsPI4P levelsRab GTPase Sec4pMembrane recruitmentRegulatory switchExchange factorSecretory pathwayVesicle maturationSec2pSec15pSecretory vesiclesPositive feedback loopYpt32pPhosphatidylinositol 4Vesicles formSec4pVesiclesSecretory sitesFeedback loopRecruitment cascadeCascadeRecruitmentPI4PRabPhosphatidylinositolGuanineA fast, single-vesicle fusion assay mimics physiological SNARE requirements
Karatekin E, Di Giovanni J, Iborra C, Coleman J, O'Shaughnessy B, Seagar M, Rothman JE. A fast, single-vesicle fusion assay mimics physiological SNARE requirements. Proceedings Of The National Academy Of Sciences Of The United States Of America 2010, 107: 3517-3521. PMID: 20133592, PMCID: PMC2840481, DOI: 10.1073/pnas.0914723107.Peer-Reviewed Original Research
2008
An Internal Domain of Exo70p Is Required for Actin-independent Localization and Mediates Assembly of Specific Exocyst Components
Hutagalung A, Coleman J, Pypaert M, Novick P. An Internal Domain of Exo70p Is Required for Actin-independent Localization and Mediates Assembly of Specific Exocyst Components. Molecular Biology Of The Cell 2008, 20: 153-163. PMID: 18946089, PMCID: PMC2613103, DOI: 10.1091/mbc.e08-02-0157.Peer-Reviewed Original ResearchMeSH KeywordsActinsAmino Acid SequenceCell MembraneExocytosisModels, MolecularMolecular Sequence DataMutationProtein Structure, TertiaryProtein SubunitsRecombinant Fusion ProteinsRho GTP-Binding ProteinsSaccharomyces cerevisiaeSaccharomyces cerevisiae ProteinsSecretory PathwayVesicular Transport ProteinsConceptsExocyst assemblyPlasma membraneHigh copy number suppressorActin-independent pathwayAmino-terminal domainSynthetic lethal interactionsRod-shaped subunitsNumber suppressorVesicle tethersExocyst componentsExocytic sitesActin cablesExo70pSingle geneSecretory vesiclesLethal interactionsSec3pSynthetic lethalityComplete deletionExocystInternal domainSubunitsDeletionMutationsVesicles
2006
The rab Exchange Factor Sec2p Reversibly Associates with the Exocyst
Medkova M, France Y, Coleman J, Novick P. The rab Exchange Factor Sec2p Reversibly Associates with the Exocyst. Molecular Biology Of The Cell 2006, 17: 2757-2769. PMID: 16611746, PMCID: PMC1474791, DOI: 10.1091/mbc.e05-10-0917.Peer-Reviewed Original ResearchConceptsSecretory vesiclesExchange factor Sec2pTemperature-sensitive growthC-terminal halfExocyst complexExocytic sitesRab GTPaseExchange factorMutant resultsMutant correlatesRecycling pathwaySec2pExocystNucleotide exchangePlasma membraneSec4pSec15pVesiclesMislocalizationEffectorsPolarized transportAssociatesGTPaseExocytosisPathway