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 platformVesiclesAssemblyCellsBilayersLeafletsSynaptotagmin rings as high-sensitivity regulators of synaptic vesicle docking and fusion
Zhu J, McDargh ZA, Li F, Krishnakumar SS, Rothman JE, O’Shaughnessy B. Synaptotagmin rings as high-sensitivity regulators of synaptic vesicle docking and fusion. Proceedings Of The National Academy Of Sciences Of The United States Of America 2022, 119: e2208337119. PMID: 36103579, PMCID: PMC9499556, DOI: 10.1073/pnas.2208337119.Peer-Reviewed Original ResearchConceptsVesicle dockingPlasma membrane domainsSynaptic vesiclesCalcium sensor synaptotagminSynaptic vesicle dockingInhibitor of fusionFusion clampSensor synaptotagminMembrane domainsTrigger fusionPlasma membraneC2AB domainAnionic phospholipid bilayersNeuronal synapsesMembrane compositionPhospholipid monolayersATP levelsVesiclesExocytotic releaseDockingPhospholipid bilayers
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
2018
Rearrangements 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 Research
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 synapsesTwo 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 tweezersComplexes
2016
Nanodisc-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