2024
Identification of the potassium-binding site in serotonin transporter
Hellsberg E, Boytsov D, Chen Q, Niello M, Freissmuth M, Rudnick G, Zhang Y, Sandtner W, Forrest L. Identification of the potassium-binding site in serotonin transporter. Proceedings Of The National Academy Of Sciences Of The United States Of America 2024, 121: e2319384121. PMID: 38652746, PMCID: PMC11067047, DOI: 10.1073/pnas.2319384121.Peer-Reviewed Original ResearchConceptsSerotonin transporterSite-directed mutagenesis of residuesMutagenesis of residuesSite-directed mutagenesisHeterologous expression systemStudy of vesiclesNa2 siteClearance of serotoninPatch-clamp recordingsExpression systemBinding residuesSequential bindingMolecular dynamics simulationsBinding sitesPotassium binding siteSubstrate accumulationClamp recordingsVesiclesResiduesTurnover rateBindingStructural studiesChemical gradientsBinding configurationsSynaptic cleft
2015
Two Na+ Sites Control Conformational Change in a Neurotransmitter Transporter Homolog*
Tavoulari S, Margheritis E, Nagarajan A, DeWitt DC, Zhang YW, Rosado E, Ravera S, Rhoades E, Forrest LR, Rudnick G. Two Na+ Sites Control Conformational Change in a Neurotransmitter Transporter Homolog*. Journal Of Biological Chemistry 2015, 291: 1456-1471. PMID: 26582198, PMCID: PMC4714228, DOI: 10.1074/jbc.m115.692012.Peer-Reviewed Original ResearchMeSH KeywordsAmino Acid SubstitutionAmino Acid Transport SystemsAquatic OrganismsBacterial ProteinsBinding SitesCysteineGram-Negative BacteriaLigandsLiposomesModels, MolecularMolecular Dynamics SimulationMutagenesis, Site-DirectedMutationPlasma Membrane Neurotransmitter Transport ProteinsProtein ConformationProtein FoldingProtein StabilityProteolipidsRecombinant ProteinsSodiumConceptsConformational changesTransmembrane helix 1Open conformational stateDependent conformational changesTransporter homologExtracellular gateProkaryotic homologCytoplasmic pathwayHelix 1Interaction networksIntermediary interactionsBiophysical assaysNeurotransmitter transportersSubstrate pathwayNa2 siteConformational statesHelix motionsLeuTDirect interactionDependent closureHomologMutantsDistinct stepsResiduesComputational analysis
2010
Reconstructing a Chloride-binding Site in a Bacterial Neurotransmitter Transporter Homologue*
Tavoulari S, Rizwan AN, Forrest LR, Rudnick G. Reconstructing a Chloride-binding Site in a Bacterial Neurotransmitter Transporter Homologue*. Journal Of Biological Chemistry 2010, 286: 2834-2842. PMID: 21115480, PMCID: PMC3024779, DOI: 10.1074/jbc.m110.186064.Peer-Reviewed Original ResearchConceptsChloride-binding siteConformational changesAdjacent binding sitesSingle point mutationProkaryotic homologuesSubstrate translocationIon-binding sitesTransporter homologueTransport proteinsNeurotransmitter transportersNeurotransmitter transportPoint mutationsBinding sitesHomologuesProteinMutationsCl(-) bindsDirect evidenceTherapeutic drugsSitesDependent formTranslocationTransportersBindsResidues
2009
Ligand Effects on Cross-linking Support a Conformational Mechanism for Serotonin Transport*
Tao Z, Zhang YW, Agyiri A, Rudnick G. Ligand Effects on Cross-linking Support a Conformational Mechanism for Serotonin Transport*. Journal Of Biological Chemistry 2009, 284: 33807-33814. PMID: 19837674, PMCID: PMC2797150, DOI: 10.1074/jbc.m109.071977.Peer-Reviewed Original ResearchConceptsN-terminal cyanogen bromide fragmentGamma-aminobutyric acid transporterCyanogen bromide fragmentsTransmembrane 1Cysteine residuesMutagenesis strategyAcid transportersConformational mechanismSerotonin transportCysteineCorresponding positionDisulfide CrossTransportersSynaptic cleftResiduesSame molecule
2007
Interaction between lysine 102 and aspartate 338 in the insect amino acid cotransporter KAAT1
Castagna M, Soragna A, Mari S, Santacroce M, Betté S, Mandela P, Rudnick G, Peres A, Sacchi V. Interaction between lysine 102 and aspartate 338 in the insect amino acid cotransporter KAAT1. American Journal Of Physiology - Cell Physiology 2007, 293: c1286-c1295. PMID: 17626242, DOI: 10.1152/ajpcell.00190.2007.Peer-Reviewed Original ResearchMeSH KeywordsAmino Acid SequenceAmino Acid SubstitutionAmino Acid Transport Systems, NeutralAnimalsAspartic AcidBinding SitesBiological TransportCross-Linking ReagentsCysteineDithiothreitolFemaleInsect ProteinsKineticsLepidopteraLysineModels, MolecularMolecular Sequence DataOocytesPhenanthrolinesPotassiumProtein Structure, TertiarySequence Homology, Amino AcidSodiumTryptophanXenopus laevisConceptsSingle cysteine mutantsNeutral amino acid transporterSite-directed mutagenesisAmino acid transportersTransport-associated currentNSS transportersDouble mutantXenopus laevis oocytesCysteine mutantsWild typeDependent transportLysine 102MutantsSuper familyAcid transportersPermeation pathwayAmino acidsDisulfide bondsLaevis oocytesFunctional evidenceAsp338Leucine uptakeKAAT1Spatial organizationResidues
2002
Chemical Modification Strategies for Structure‐Function Studies
Rudnick G. Chemical Modification Strategies for Structure‐Function Studies. 2002, 125-141. DOI: 10.1002/0471434043.ch8.ChaptersTransmembrane domainConformational changesPolytopic membrane proteinsStructure-function studiesMembrane proteinsTransporter proteinsReactive residuesLipid bilayersProteinTransportersExternal faceExternal loopChemical modification strategiesDomainChemical modificationSubstrateCysteineResiduesSitesMembraneModificationBilayers
2000
Functional Role of Critical Stripe Residues in Transmembrane Span 7 of the Serotonin Transporter EFFECTS OF Na+, Li+, AND METHANETHIOSULFONATE REAGENTS*
Kamdar G, Penado K, Rudnick G, Stephan M. Functional Role of Critical Stripe Residues in Transmembrane Span 7 of the Serotonin Transporter EFFECTS OF Na+, Li+, AND METHANETHIOSULFONATE REAGENTS*. Journal Of Biological Chemistry 2000, 276: 4038-4045. PMID: 11058600, DOI: 10.1074/jbc.m008483200.Peer-Reviewed Original ResearchConceptsCys-109Methanethiosulfonate reagentsWater-filled poresNative cysteine residuesCysteine-containing mutantsExtracellular loop 1Close-contact regionThree-dimensional structureCysteine residuesTranslocation mechanismControl mutantsAlpha-helixMTSEA-biotinResidue positionsCysteine substitutionsLoop 1Conformational changesMTS reagentsFunctional roleMutantsIon bindingResiduesTransportersIon dependenceSerotonin transporter
1998
Critical Amino Acid Residues in Transmembrane Span 7 of the Serotonin Transporter Identified by Random Mutagenesis*
Penado K, Rudnick G, Stephan M. Critical Amino Acid Residues in Transmembrane Span 7 of the Serotonin Transporter Identified by Random Mutagenesis*. Journal Of Biological Chemistry 1998, 273: 28098-28106. PMID: 9774428, DOI: 10.1074/jbc.273.43.28098.Peer-Reviewed Original ResearchMeSH KeywordsAmino Acid SequenceAnimalsBiological TransportCarrier ProteinsMembrane GlycoproteinsMembrane Transport ProteinsModels, MolecularMolecular Sequence DataMutagenesisNerve Tissue ProteinsProtein ConformationRatsSerotoninSerotonin Plasma Membrane Transport ProteinsStructure-Activity RelationshipConceptsAmino acid residuesRandom mutagenesisAcid residuesTransport activityCritical amino acid residuesRat brain serotonin transporterCritical residuesTransport cycleWild typeNonconservative mutationsStructural predictionsTransporter functionLater stepsMutationsSerotonin transporterResiduesMutagenesisHydrophobic substitutionsTyr-385TransportersMutantsActivitySubstitutionNearby positions