Venkat Kalyana Sundaram, PhD
Research Scientist in Cell BiologyCards
About
Research
Publications
Featured Publications
Native Planar Asymmetric Suspended Membrane for Single‐Molecule Investigations: Plasma Membrane on a Chip
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 2022, 18: e2205567. PMID: 36328714, DOI: 10.1002/smll.202205567.Peer-Reviewed Original ResearchConceptsPlasma membraneProtein assembliesNative plasma membrane vesiclesTotal internal reflection fluorescence microscopySingle-molecule levelSingle-molecule investigationsCellular plasma membranePlasma membrane vesiclesSingle-molecule precisionReflection fluorescence microscopyKnowledge of lipidProtein complexesProtein architectureCell signalingMovement of moleculesProtein orientationLipid membranesBiological processesCellular membranesMembrane vesiclesMicroarray platformFluorescence investigationsLipid domainsFluorescence microscopyMembraneMunc13 structural transitions and oligomers that may choreograph successive stages in vesicle priming for neurotransmitter release
Grushin K, Kalyana Sundaram RV, Sindelar CV, Rothman JE. Munc13 structural transitions and oligomers that may choreograph successive stages in vesicle priming for neurotransmitter release. Proceedings Of The National Academy Of Sciences Of The United States Of America 2022, 119: e2121259119. PMID: 35135883, PMCID: PMC8851502, DOI: 10.1073/pnas.2121259119.Peer-Reviewed Original ResearchMunc13 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 membraneSNAP25AssemblyBindingRecruitsRoles 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
2025
Two successive oligomeric Munc13 assemblies scaffold vesicle docking and SNARE assembly to support neurotransmitter release
Bera M, Grushin K, Kalyana Sundaram R, Hinzen J, Chen J, Chatterjee A, Radhakrishnan A, Lee S, Padmanarayana M, Coleman J, Pincet F, Rothman J, Dittman J. Two successive oligomeric Munc13 assemblies scaffold vesicle docking and SNARE assembly to support neurotransmitter release. Nature Communications 2025, 16: 7222. PMID: 40764329, PMCID: PMC12325603, DOI: 10.1038/s41467-025-62420-7.Peer-Reviewed Original ResearchConceptsVesicle dockingSynaptic vesiclesPriming of synaptic vesiclesPresynaptic plasma membraneFusion in vitroTrans-SNARESNARE assemblyVesicle primingFunction in vivoMunc13Oligomeric assembliesHomo-oligomersInterface mutationsPlasma membraneNeurotransmitter secretionFunctional impactNeurotransmitter releaseVesiclesSnareIn vivoAssemblyIn vitroDockingMutationsSequenceHighly stable planar asymmetric suspended membranes for investigating protein dynamics and membrane fusion
Bera M, Kalyana Sundaram R, Coleman J, Chatterjee A, Thoduvayil S, Pincet F, Ramakrishnan S. Highly stable planar asymmetric suspended membranes for investigating protein dynamics and membrane fusion. Nature Protocols 2025, 20: 3582-3606. PMID: 40461798, DOI: 10.1038/s41596-025-01192-2.Peer-Reviewed Original ResearchMembrane fusionSingle-vesicle fusion assayMembrane fusion eventsProtein dynamics analysisMembrane fusion mechanismFluorescently labeled proteinsProtein-lipid interactionsSNARE proteinsTotal internal reflection fluorescenceFusion eventsMolecular chaperonesInvestigate protein dynamicsTime-lapse imagingCellular signalingLipid asymmetryFusion assayBiological processesLipid membranesProtein dynamicsMembrane model systemsLiving cellsMembrane environmentNear-native environmentMolecular componentsReflection fluorescence
2024
Quantitative single-molecule analysis of assembly and Ca2+-dependent disassembly of synaptotagmin oligomers on lipid bilayers
Li F, Coleman J, Redondo-Morata L, Kalyana Sundaram R, Stroeva E, Rothman J, Pincet F. Quantitative single-molecule analysis of assembly and Ca2+-dependent disassembly of synaptotagmin oligomers on lipid bilayers. Communications Biology 2024, 7: 1608. PMID: 39627539, PMCID: PMC11615320, DOI: 10.1038/s42003-024-07317-9.Peer-Reviewed Original ResearchConceptsSyt-1Lipid bilayerRing-like oligomersCa2+-evoked releaseSynaptotagmin-1Single-molecule imaging methodsSynaptic vesiclesBiochemical evidencePhysiological requirementsOligomerizationAnalysis of assembliesBilayerOligomersCa2+LipidAssemblyCa2Classes of oligomersMutationsVesiclesDisassemblyEvoked release
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 actionProteinAssemblyChaperonesSynaptotagminExocytosisBilayersRapid Quantification of First and Second Phase Insulin Secretion Dynamics using an In vitro Platform for Improving Insulin Therapy
Thoduvayil S, Weerakkody J, Sundaram R, Topper M, Bera M, Coleman J, Li X, Mariappan M, Ramakrishnan S. Rapid Quantification of First and Second Phase Insulin Secretion Dynamics using an In vitro Platform for Improving Insulin Therapy. Cell Calcium 2023, 113: 102766. PMID: 37295201, PMCID: PMC10450995, DOI: 10.1016/j.ceca.2023.102766.Peer-Reviewed Original ResearchConceptsCellular pathwaysSecretion dynamicsSmall molecule screeningLuciferase reporter systemInsulin secretion dynamicsHigh-throughput compoundInsulin secretionHigh-throughput quantificationReporter systemGenetic studiesLive cellsDistinct rolesInsulin therapyGlucose-stimulated insulin secretionSmall moleculesEffective insulin therapyPathwaySecretionRapid Quantification of First and Second Phase Insulin Secretion Dynamics using an In vitro Platform for Improving Insulin Therapy
Sikha Thoduvayil, Jonathan S. Weerakkody, Ramalingam Venkat Kalyana Sundaram, Mackenzie Topper, Manindra Bera, Jeff Coleman, Xia Li, Malaiyalam Mariappan, Sathish Ramakrishnan. Rapid Quantification of First and Second Phase Insulin Secretion Dynamics using an In vitro Platform for Improving Insulin Therapy, Cell Calcium, Volume 113, 2023, 102766, ISSN 0143-4160, https://doi.org/10.1016/j.ceca.2023.102766. (https://www.sciencedirect.com/science/article/pii/S0143416023000787)Peer-Reviewed Original Research In Press