2018
Structural elements required for coupling ion and substrate transport in the neurotransmitter transporter homolog LeuT
Zhang YW, Tavoulari S, Sinning S, Aleksandrova AA, Forrest LR, Rudnick G. Structural elements required for coupling ion and substrate transport in the neurotransmitter transporter homolog LeuT. Proceedings Of The National Academy Of Sciences Of The United States Of America 2018, 115: e8854-e8862. PMID: 30181291, PMCID: PMC6156673, DOI: 10.1073/pnas.1716870115.Peer-Reviewed Original ResearchConceptsTransporter domainConformational changesOpen stateSodium symporter familyIon-substrate couplingTransmembrane ion gradientsSymporter familyNSS transportersSubstrate bindingLeuTIntracellular substratesCysteine accessibilitySubstrate transportAccessibility of substrateTyrosine residuesConformational responseNa2 siteUncoupled movementIon gradientsExtracellular pathwaysMechanistic componentsTransportersProteinTransport of ionsBinding
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
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
2008
Mechanism for alternating access in neurotransmitter transporters
Forrest LR, Zhang YW, Jacobs MT, Gesmonde J, Xie L, Honig BH, Rudnick G. Mechanism for alternating access in neurotransmitter transporters. Proceedings Of The National Academy Of Sciences Of The United States Of America 2008, 105: 10338-10343. PMID: 18647834, PMCID: PMC2480614, DOI: 10.1073/pnas.0804659105.Peer-Reviewed Original ResearchConceptsNeurotransmitter transportersMammalian neurotransmitter transportersMammalian serotonin transporterTransmembrane helix 1Bacterial homologueIon-binding sitesTransporter familyExtensive mutagenesisHelix 1Similar repeatsLeuTConformational changesSerotonin transporterRepeatsAlternate conformationConformational differencesExtracellular pathwaysCytoplasmTransportersExtracellular spaceCysteine reagentCrystal structureConformationPathwayAccessibility measurements
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
2001
A Conformationally Sensitive Residue on the Cytoplasmic Surface of Serotonin Transporter*
Androutsellis-Theotokis A, Ghassemi F, Rudnick G. A Conformationally Sensitive Residue on the Cytoplasmic Surface of Serotonin Transporter*. Journal Of Biological Chemistry 2001, 276: 45933-45938. PMID: 11592963, DOI: 10.1074/jbc.m107462200.Peer-Reviewed Original ResearchA Lithium-induced Conformational Change in Serotonin Transporter Alters Cocaine Binding, Ion Conductance, and Reactivity of Cys-109*
Ni Y, Chen J, Androutsellis-Theotokis A, Huang C, Moczydlowski E, Rudnick G. A Lithium-induced Conformational Change in Serotonin Transporter Alters Cocaine Binding, Ion Conductance, and Reactivity of Cys-109*. Journal Of Biological Chemistry 2001, 276: 30942-30947. PMID: 11408487, DOI: 10.1074/jbc.m104653200.Peer-Reviewed Original Research
1998
Determination of External Loop Topology in the Serotonin Transporter by Site-directed Chemical Labeling*
Chen J, Liu-Chen S, Rudnick G. Determination of External Loop Topology in the Serotonin Transporter by Site-directed Chemical Labeling*. Journal Of Biological Chemistry 1998, 273: 12675-12681. PMID: 9575231, DOI: 10.1074/jbc.273.20.12675.Peer-Reviewed Original Research
1997
The Third Transmembrane Domain of the Serotonin Transporter Contains Residues Associated with Substrate and Cocaine Binding*
Chen J, Sachpatzidis A, Rudnick G. The Third Transmembrane Domain of the Serotonin Transporter Contains Residues Associated with Substrate and Cocaine Binding*. Journal Of Biological Chemistry 1997, 272: 28321-28327. PMID: 9353288, DOI: 10.1074/jbc.272.45.28321.Peer-Reviewed Original ResearchAsparagineBinding SitesCarrier ProteinsCell LineCell MembraneCocaineCysteineEthyl MethanesulfonateHumansIndicators and ReagentsIsoleucineLigandsMembrane GlycoproteinsMembrane Transport ProteinsMesylatesMutagenesis, Site-DirectedNerve Tissue ProteinsProtein Structure, SecondarySerotoninSerotonin Plasma Membrane Transport ProteinsStructure-Activity RelationshipTyrosineExternal Cysteine Residues in the Serotonin Transporter †
Chen J, Liu-Chen S, Rudnick G. External Cysteine Residues in the Serotonin Transporter †. Biochemistry 1997, 36: 1479-1486. PMID: 9063896, DOI: 10.1021/bi962256g.Peer-Reviewed Original ResearchConceptsTransport activityMTS reagentsCysteine residuesWild typeWild-type transporterSecond external loopTransient expression systemSurface expressionRat serotonin transporterExternal cysteine residuesHydropathy analysisMutant transportersType transporterDouble mutantExpression systemMethanethiosulfonate reagentsLigand bindingSerotonin transporterMutantsExtracellular loopHeLa cellsDisulfide bondsPartial activityTransportersSerine
1994
Human norepinephrine transporter. Biosynthetic studies using a site-directed polyclonal antibody.
Melikian H, McDonald J, Gu H, Rudnick G, Moore K, Blakely R. Human norepinephrine transporter. Biosynthetic studies using a site-directed polyclonal antibody. Journal Of Biological Chemistry 1994, 269: 12290-12297. PMID: 8163533, DOI: 10.1016/s0021-9258(17)32714-x.Peer-Reviewed Original ResearchAnimalsAntibodiesCarrier ProteinsCell LineCysteineElectrophoresis, Polyacrylamide GelEnzyme-Linked Immunosorbent AssayFluorescent Antibody TechniqueHeLa CellsHumansImmunoblottingKineticsMethionineMolecular WeightNorepinephrineNorepinephrine Plasma Membrane Transport ProteinsRabbitsSulfur RadioisotopesSymportersTransfectionTunicamycin