Sathish Ramakrishnan, PhD
Assistant ProfessorCards
About
Research
Publications
Featured Publications
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 roleFusionExocytosisMachineryProteinBindsMechanismMolecular 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 functionDomainHelixVesiclesFunctionMembraneInteractionNative 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 microscopyMembraneHighly 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 fluorescencePhotosensitive Nanoprobes for Rapid High Purity Isolation and Size‐Specific Enrichment of Synthetic and Extracellular Vesicle Subpopulations (Adv. Funct. Mater. 34/2024)
Weerakkody J, Tseng T, Topper M, Thoduvayil S, Radhakrishnan A, Pincet F, Kyriakides T, Gunasekara R, Ramakrishnan S. Photosensitive Nanoprobes for Rapid High Purity Isolation and Size‐Specific Enrichment of Synthetic and Extracellular Vesicle Subpopulations (Adv. Funct. Mater. 34/2024). Advanced Functional Materials 2024, 34 DOI: 10.1002/adfm.202470191.Peer-Reviewed Original ResearchVesicle biogenesisExtracellular vesicle subpopulationsLipid nanoprobesVesicle subpopulationsNative extracellular vesiclesVesicle populationsSeparate vesiclesPurity isolationExtracellular vesiclesVesiclesCellular originHydrophobic interactionsBiogenesisSize variabilitySubpopulationsIsolatesExtracellularSynaptophysin 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 actionProteinAssemblyChaperonesSynaptotagminExocytosisBilayersPRRT2 Regulates Synaptic Fusion by Directly Modulating SNARE Complex Assembly
Coleman J, Jouannot O, Ramakrishnan SK, Zanetti MN, Wang J, Salpietro V, Houlden H, Rothman JE, Krishnakumar SS. PRRT2 Regulates Synaptic Fusion by Directly Modulating SNARE Complex Assembly. Cell Reports 2018, 22: 820-831. PMID: 29346777, PMCID: PMC5792450, DOI: 10.1016/j.celrep.2017.12.056.Peer-Reviewed Original ResearchConceptsProline-rich transmembrane protein 2SNARE complex assemblyComplex assemblyTrans-SNARE complex assemblyTerminal proline-rich domainSynaptic SNARE proteinsProline-rich domainParoxysmal neurological disordersSynaptic vesicle primingLive-cell imagingTransmembrane protein 2Synaptic fusionSNARE proteinsVesicle primingSingle exocytotic eventsBiophysical analysisFusion assaysMolecular mechanismsFunction mutationsPhysiological roleExocytotic eventsPre-synaptic terminalsPC12 cellsProtein 2Single vesiclesHigh-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
2025
Biomimetic membrane in a microfluidic chip for the electrical and optical monitoring of biological reactions
Mion D, Bunel L, Ramakrishnan S, Heo P, Pincet F. Biomimetic membrane in a microfluidic chip for the electrical and optical monitoring of biological reactions. Nature Protocols 2025, 20: 3477-3508. PMID: 40461799, DOI: 10.1038/s41596-025-01171-7.Peer-Reviewed Original ResearchMicrofluidic chipTwo-dimensional bilayersBiomimetic membranesChip fabricationSingle-particleMicrofluidic channelOptical microscopyElectrical readoutResin moldMicrofluidic setupMembrane typeOptical monitoringChipPoly(dimethylsiloxaneBiological membranesPhysicochemical cuesFluid lipidsBilayerCharacteristics of biological membranesChannelComprehensive procedureBilayer leafletsMolecular reactions
2024
Photosensitive Nanoprobes for Rapid High Purity Isolation and Size‐Specific Enrichment of Synthetic and Extracellular Vesicle Subpopulations
Weerakkody J, Tseng T, Topper M, Thoduvayil S, Radhakrishnan A, Pincet F, Kyriakides T, Gunasekara R, Ramakrishnan S. Photosensitive Nanoprobes for Rapid High Purity Isolation and Size‐Specific Enrichment of Synthetic and Extracellular Vesicle Subpopulations. Advanced Functional Materials 2024, 34 PMID: 39372670, PMCID: PMC11452007, DOI: 10.1002/adfm.202400390.Peer-Reviewed Original ResearchExtracellular vesicle subpopulationsVesicle subpopulationsIsolation of vesiclesPurity extracellular vesiclesRelease of vesiclesAnalysis of nucleic acidsNear-native formLarge-scale isolationLipid nanoprobesDownstream analysisPurity isolationEfficient isolationVesiclesSynthetic vesiclesNucleic acidsExtracellular vesiclesIsolation methodIsolatesBiomarker discoveryExposure to lightSubpopulationsEnrichmentProteinComplex biological mediaCleavage
Academic Achievements & Community Involvement
News
News
Get In Touch
Contacts
Academic Office Number