2023
Direct 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
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
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 insertionMechanisms 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 step
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
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