2024
Synaptotagmin-1 and synaptotagmin-7 synergistically regulate the timing and plasticity of Ca2+-evoked vesicular release process
Bose D, Bera M, Norman C, Volynski K, Krishnakumar S. Synaptotagmin-1 and synaptotagmin-7 synergistically regulate the timing and plasticity of Ca2+-evoked vesicular release process. Biophysical Journal 2024, 123: 381a. DOI: 10.1016/j.bpj.2023.11.2327.Peer-Reviewed Original Research
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 actionProteinAssemblyChaperonesSynaptotagminExocytosisBilayersTurbocharging synaptic transmission
Rothman J, Grushin K, Bera M, Pincet F. Turbocharging synaptic transmission. FEBS Letters 2023, 597: 2233-2249. PMID: 37643878, DOI: 10.1002/1873-3468.14718.Peer-Reviewed Original ResearchRoles 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 caReconstitutionVAMP2ComplexinMutationsRapid 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 therapyPathwaySecretion
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 platformVesiclesAssemblyCellsBilayersLeafletsNative 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 microscopyMembraneMolecular 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
2020
Pulling the springs of a cell by single-molecule force spectroscopy
Mukherjee C, Bera M, Ainavarapu S, Sengupta K. Pulling the springs of a cell by single-molecule force spectroscopy. Emerging Topics In Life Sciences 2020, 5: 77-87. PMID: 33284963, DOI: 10.1042/etls20200254.Peer-Reviewed Original ResearchConceptsSingle-molecule force spectroscopyFilamentous proteinsForce spectroscopyExtracellular matrix proteinsNucleoskeletal proteinsTraction forceMatrix proteinsNecessary anchorageProteinIntermediate filamentsWhole cellsCurrent understandingTissue repairFundamental unitCellsBiochemical changesFibrillar networkMechanotransductionMicrotubulesMicrofilamentsECMFilamentsRegenerationNucleusRETREG1/FAM134B mediated autophagosomal degradation of AMFR/GP78 and OPA1 —a dual organellar turnover mechanism
Mookherjee D, Das S, Mukherjee R, Bera M, Jana S, Chakrabarti S, Chakrabarti O. RETREG1/FAM134B mediated autophagosomal degradation of AMFR/GP78 and OPA1 —a dual organellar turnover mechanism. Autophagy 2020, 17: 1729-1752. PMID: 32559118, PMCID: PMC8354597, DOI: 10.1080/15548627.2020.1783118.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsAutophagosomesCell Line, TumorChlorocebus aethiopsCOS CellsGene Knockdown TechniquesGTP PhosphohydrolasesHeLa CellsHumansIntracellular Signaling Peptides and ProteinsLysosomesMembrane ProteinsMicroscopy, ConfocalMicroscopy, Electron, TransmissionReal-Time Polymerase Chain ReactionReceptors, Autocrine Motility FactorConceptsInner mitochondrial membraneRETREG1/FAM134BEndoplasmic reticulumMitochondrial membraneFluorescent proteinAutophagosomal degradationOuter mitochondrial membrane proteinMahogunin Ring Finger-1OPA1 mitochondrial dynaminMicrotubule associated protein 1 light chain 3Outer mitochondrial membrane 20AMFR/gp78Cellular surveillance systemsMitochondrial membrane proteinInteresting new geneAutocrine motility factor receptorOuter mitochondrial membraneLC3-interacting regionMAP1LC3/LC3Protein 1 light chain 3Blue fluorescent proteinSQSTM1/p62Green fluorescent proteinRed fluorescent proteinReticulophagy regulator 1Synergistic 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 roleFusionExocytosisMachineryProteinBindsMechanismDissecting the Synergistic Roles of Synaptotagmin and Complexin in Ca2+-Regulated Exocytosis
Ramakrishnan S, Bera M, Coleman J, Pincet F, Rothman J, Krishnakumar S. Dissecting the Synergistic Roles of Synaptotagmin and Complexin in Ca2+-Regulated Exocytosis. Biophysical Journal 2020, 118: 488a. DOI: 10.1016/j.bpj.2019.11.2702.Peer-Reviewed Original ResearchNuclear filaments: role in chromosomal positioning and gene expression
Bera M, Sengupta K. Nuclear filaments: role in chromosomal positioning and gene expression. Nucleus 2020, 11: 99-110. PMID: 32453974, PMCID: PMC7529408, DOI: 10.1080/19491034.2020.1769445.Peer-Reviewed Original ResearchConceptsChromosomal contactsGene expressionLMNA mutationsInner nuclear membraneDNA damage repairGene expression profilesIntrachromosomal contactsChromosomal positioningChromosome positioningNuclear actinNuclear laminsEpigenetic modificationsLamin networkChromosomal loopsDamage repairExpression profilesNuclear membraneNuclear processesKey playersLaminsLaminopathiesMutationsElastic meshworkMuscle tissueMechanical rigidity
2019
Chromosome Territorial Organization Drives Efficient Protein Complex Formation: A Hypothesis.
Bera M, Kalyana Sundaram RV. Chromosome Territorial Organization Drives Efficient Protein Complex Formation: A Hypothesis. The Yale Journal Of Biology And Medicine 2019, 92: 541-548. PMID: 31543715, PMCID: PMC6747946.Peer-Reviewed Original ResearchConceptsProtein complex assemblyProtein complex formationNascent protein chainNuclear basketExport factorsProtein complexesComplex assemblyNuclear granulesKissing loopProtein chainsEukaryotesMRNAComplex formationComplex formation efficiencyChromosomesERPathwayAssemblyLoopInterphaseComplexesGranulesTranslationFormationExportSynaptotagmin 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
2016
Significance of 1B and 2B domains in modulating elastic properties of lamin A
Bera M, Ainavarapu S, Sengupta K. Significance of 1B and 2B domains in modulating elastic properties of lamin A. Scientific Reports 2016, 6: 27879. PMID: 27301336, PMCID: PMC4908593, DOI: 10.1038/srep27879.Peer-Reviewed Original ResearchConceptsLamin ASingle-molecule force spectroscopyRod domainType V intermediate filament proteinsLamin rod domainsSingle molecular levelInner nuclear membraneC-terminal domainIntermediate filament proteinsForce spectroscopyNuclear laminsLaminsNuclear membraneFilament proteinsElastic meshworkNuclear shapeMutationsComparable mechanical propertiesDomainViscoelastic behaviorSpectroscopyLaminopathiesProperties
2014
Characterization of Unfolding Mechanism of Human Lamin A Ig Fold by Single-Molecule Force SpectroscopyImplications in EDMD
Bera M, Kotamarthi H, Dutta S, Ray A, Ghosh S, Bhattacharyya D, Ainavarapu S, Sengupta K. Characterization of Unfolding Mechanism of Human Lamin A Ig Fold by Single-Molecule Force SpectroscopyImplications in EDMD. Biochemistry 2014, 53: 7247-7258. PMID: 25343322, DOI: 10.1021/bi500726f.Peer-Reviewed Original ResearchConceptsIg domainsBasic nuclear processesB-type laminsC-terminal domainHelical rod domainAutosomal dominant Emery-Dreifuss muscular dystrophySingle-molecule force spectroscopyEmery-Dreifuss muscular dystrophyIntermediate filament proteinsHuman laminLamin proteinsNuclear laminaLamin ALamin A.Nuclear envelopeRod domainNuclear processesUnfolding mechanismFilament proteinsMisshapen nucleiCausative mutationsKey playersR453WLaminsMutations