2021
The structural basis of function and regulation of neuronal cotransporters NKCC1 and KCC2
Zhang S, Zhou J, Zhang Y, Liu T, Friedel P, Zhuo W, Somasekharan S, Roy K, Zhang L, Liu Y, Meng X, Deng H, Zeng W, Li G, Forbush B, Yang M. The structural basis of function and regulation of neuronal cotransporters NKCC1 and KCC2. Communications Biology 2021, 4: 226. PMID: 33597714, PMCID: PMC7889885, DOI: 10.1038/s42003-021-01750-w.Peer-Reviewed Original ResearchConceptsCryo-electron microscopy structureHuman NKCC1Microscopy structureEssential residuesFunctional characterizationKCC transportersPlasma membraneStructural basisTransepithelial saltTransport activityMechanistic understandingTransportersStructural studiesCritical roleCotransporter NKCC1Computational analysisIon transportWater transportNeuronal excitabilityNKCC1PhosphorylationCell volumeNKCCKCC2Residues
2014
Molecular Motions Involved in Na-K-Cl Cotransporter-mediated Ion Transport and Transporter Activation Revealed by Internal Cross-linking between Transmembrane Domains 10 and 11/12*
Monette MY, Somasekharan S, Forbush B. Molecular Motions Involved in Na-K-Cl Cotransporter-mediated Ion Transport and Transporter Activation Revealed by Internal Cross-linking between Transmembrane Domains 10 and 11/12*. Journal Of Biological Chemistry 2014, 289: 7569-7579. PMID: 24451383, PMCID: PMC3953270, DOI: 10.1074/jbc.m113.542258.Peer-Reviewed Original ResearchMeSH KeywordsAmino Acid SequenceBinding SitesCell LineChloridesCopperCross-Linking ReagentsDisulfidesHomeostasisHumansIon TransportIonsKineticsMicroscopy, ConfocalMicroscopy, FluorescenceModels, MolecularMolecular Sequence DataMutationPhenanthrolinesPhosphorylationProtein Structure, TertiaryRubidium RadioisotopesSequence Homology, Amino AcidSodium-Potassium-Chloride SymportersSolute Carrier Family 12, Member 2ConceptsTransmembrane domain 10Domain 10Copper phenanthrolineLarge C terminusNa-K-Cl cotransporterRegulatory domainCysteine pairsC-terminusN-terminusDephosphorylation rateTransporter activationDisulfide formationIon transportHomology modelNKCC activationInhibition of transportTransport functionLow micromolar concentrationsSame transporterCross-link formationActivation statePhosphorylationTerminusTransportersOcclusion step
2012
Loop Diuretic and Ion-binding Residues Revealed by Scanning Mutagenesis of Transmembrane Helix 3 (TM3) of Na-K-Cl Cotransporter (NKCC1)*
Somasekharan S, Tanis J, Forbush B. Loop Diuretic and Ion-binding Residues Revealed by Scanning Mutagenesis of Transmembrane Helix 3 (TM3) of Na-K-Cl Cotransporter (NKCC1)*. Journal Of Biological Chemistry 2012, 287: 17308-17317. PMID: 22437837, PMCID: PMC3366785, DOI: 10.1074/jbc.m112.356014.Peer-Reviewed Original ResearchConceptsTransmembrane helix 3Na-K-Cl cotransporterTranslocation pathwayHelix 3Homology modelTryptophan-scanning mutagenesisMutation of residuesStructural homology modelEpithelial salt transportExtracellular gateCellular chloride homeostasisScanning mutagenesisOpen conformationIntracellular endPore residuesFunctional roleIon translocationTranslocation rateResiduesMutagenesisCentral roleChloride homeostasisMutationsPathwayLarge effect
2004
WNK4 regulates apical and basolateral Cl– flux in extrarenal epithelia
Kahle KT, Gimenez I, Hassan H, Wilson FH, Wong RD, Forbush B, Aronson PS, Lifton RP. WNK4 regulates apical and basolateral Cl– flux in extrarenal epithelia. Proceedings Of The National Academy Of Sciences Of The United States Of America 2004, 101: 2064-2069. PMID: 14769928, PMCID: PMC357052, DOI: 10.1073/pnas.0308434100.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsBlotting, WesternCarrier ProteinsCell PolarityChloridesEpitheliumHumansImmunohistochemistryIon TransportKidneyMembrane ProteinsMembrane Transport ProteinsMiceOocytesProtein Serine-Threonine KinasesRNA, MessengerSodium-Potassium-Chloride SymportersSolute Carrier Family 12, Member 2Sulfate TransportersXenopus laevisConceptsCl fluxBlood-brain barrierUnrelated ion channelsActivity of mediatorsWNK4 mRNABile ductPancreatic ductExtrarenal expressionExtrarenal tissuesCl(-) handlingPseudohypoaldosteronism type IIChannel ROMKNaCl reabsorptionSerine-threonine kinase WNK4Specialized endotheliumExchanger SLC26A6NaCl cotransporterWNK4 effectsColonic cryptsEpitheliumVariable inhibitionSweat ductsTight junctionsKidneyElectrolyte flux
2002
A Regulatory Locus of Phosphorylation in the N Terminus of the Na-K-Cl Cotransporter, NKCC1*
Darman RB, Forbush B. A Regulatory Locus of Phosphorylation in the N Terminus of the Na-K-Cl Cotransporter, NKCC1*. Journal Of Biological Chemistry 2002, 277: 37542-37550. PMID: 12145304, DOI: 10.1074/jbc.m206293200.Peer-Reviewed Original ResearchMeSH KeywordsAmino Acid SequenceAnimalsBinding SitesCell LineDogfishHumansIon TransportKineticsModels, MolecularPeptide FragmentsPhosphopeptidesPhosphorylationProtein ConformationRecombinant ProteinsSalt GlandSodium-Potassium-Chloride SymportersSolute Carrier Family 12, Member 2Spectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationTransfectionTrypsinConceptsProtein phosphatase 1 bindsN-terminusSer/ThrPhosphorylation-dependent mechanismN-terminal domainStrong consensus siteNa-K-Cl cotransporter NKCC1Matrix-assisted laser desorption ionization timePhosphoregulatory mechanismsPhosphoacceptor sitesRegulatory lociHEK-293 cellsNa-K-Cl cotransporterLaser desorption ionization timeCalyculin AConsensus sitesPhosphorylation stoichiometryDesorption ionization timeAmino acidsTryptic fragmentsProteinGland tubulesRectal gland tubulesFlight mass spectrometryIonization timeActivation of the Na-K-Cl Cotransporter NKCC1 Detected with a Phospho-specific Antibody*
Flemmer AW, Giménez I, Dowd BF, Darman RB, Forbush B. Activation of the Na-K-Cl Cotransporter NKCC1 Detected with a Phospho-specific Antibody*. Journal Of Biological Chemistry 2002, 277: 37551-37558. PMID: 12145305, DOI: 10.1074/jbc.m206294200.Peer-Reviewed Original ResearchMeSH KeywordsAmino Acid SequenceAnimalsAntibody SpecificityBinding SitesColonDipeptidesEpinephrineHumansIon TransportIsoproterenolKineticsMolecular Sequence DataMutagenesis, Site-DirectedPhosphatesPhosphopeptidesRatsRecombinant ProteinsSodium-Potassium-Chloride SymportersSolute Carrier Family 12, Member 2ThreonineTracheaConceptsPhospho-specific antibodiesNa-K-Cl cotransporter NKCC1Divergent vertebrate speciesBasolateral membraneShark rectal glandPhosphorylation of NKCC1Regulatory lociHEK-293 cellsHigh conservationThreonine residuesPhosphorylation experimentsVertebrate speciesRegulatory domainCotransporter NKCC1NKCC1 regulationN-terminusRectal glandCell membranePhosphorylationImmunofluorescence analysisAgonist stimulationActivation stateGland tubulesRectal gland tubulesEpithelial cells
2001
Ion transport and ligand binding by the Na–K–Cl cotransporter, structure–function studies
Isenring P, Forbush B. Ion transport and ligand binding by the Na–K–Cl cotransporter, structure–function studies. Comparative Biochemistry And Physiology Part A Molecular & Integrative Physiology 2001, 130: 487-497. PMID: 11913460, DOI: 10.1016/s1095-6433(01)00420-2.Peer-Reviewed Original ResearchMeSH KeywordsHumansIon TransportLigandsMutagenesisSodium-Potassium-Chloride SymportersStructure-Activity RelationshipConceptsNa-K-Cl cotransporterK-Cl cotransporterCation-Cl(-) cotransportersC-terminusStructure-function studiesGroups of residuesTransmembrane segmentsMutational approachAnimal cellsCentral domainVariant residuesLigand bindingIon transportDistinct carriersNa-Cl cotransporterResiduesSpecies differencesCotransporterBindingLoop diureticsAnion transportAvailable sulfhydryl groupsSulfhydryl groupsMovement of NaDifferent substratesModulation of Ion Transport by Direct Targeting of Protein Phosphatase Type 1 to the Na-K-Cl Cotransporter*
Darman R, Flemmer A, Forbush B. Modulation of Ion Transport by Direct Targeting of Protein Phosphatase Type 1 to the Na-K-Cl Cotransporter*. Journal Of Biological Chemistry 2001, 276: 34359-34362. PMID: 11466303, DOI: 10.1074/jbc.c100368200.Peer-Reviewed Original ResearchConceptsProtein phosphatase 1Substrate proteinsNa-K-Cl cotransporterProtein phosphatase type 1Phosphatase type 1Intracellular chloride regulationPhosphatase specificityRegulatory phosphorylationPhosphatase 1Catalytic subunitMotif bindsSubunit bindsN-terminusPP1cMajor proteinsDirect bindingDirect interactionChloride regulationProteinGeneral mechanismDirect targetingMutantsMotifSubunitsBinds
1998
The Na-K-Cl Cotransporters
Haas M, Forbush B. The Na-K-Cl Cotransporters. Journal Of Bioenergetics And Biomembranes 1998, 30: 161-172. PMID: 9672238, DOI: 10.1023/a:1020521308985.Peer-Reviewed Original ResearchConceptsNa-K-Cl cotransporterNa-K-ClNa-K-Cl cotransport activityNa-K-Cl cotransporter isoformsCotransport activitySecretory epitheliaApical Cl- channelsHypokalemic metabolic alkalosisCation-chloride cotransportersNKCC2 geneCl- channelsBartter's syndromeVolume depletionBasolateral membraneCotransporter proteinApical membraneSalt wastingMetabolic alkalosisSecreting epitheliaNonepithelial cellsAscending limbHenle's loopK-ClCotransporterEpithelial cells