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
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
1998
Mutagenic Mapping of the Na-K-Cl Cotransporter for Domains Involved in Ion Transport and Bumetanide Binding
Isenring P, Jacoby S, Chang J, Forbush B. Mutagenic Mapping of the Na-K-Cl Cotransporter for Domains Involved in Ion Transport and Bumetanide Binding. The Journal Of General Physiology 1998, 112: 549-558. PMID: 9806964, PMCID: PMC2229443, DOI: 10.1085/jgp.112.5.549.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsBinding SitesBumetanideCarrier ProteinsCells, CulturedChloridesDiureticsHumansKidneyKineticsMutagenesis, Site-DirectedOligonucleotide ProbesPotassiumProtein Structure, TertiaryRecombinant Fusion ProteinsRubidium RadioisotopesSharksSodiumSodium-Potassium-Chloride SymportersSpecies Specificity
1993
Molecular cloning and immunological characterization of the gamma polypeptide, a small protein associated with the Na,K-ATPase.
Mercer R, Biemesderfer D, Bliss D, Collins J, Forbush B. Molecular cloning and immunological characterization of the gamma polypeptide, a small protein associated with the Na,K-ATPase. Journal Of Cell Biology 1993, 121: 579-586. PMID: 8387529, PMCID: PMC2119561, DOI: 10.1083/jcb.121.3.579.Peer-Reviewed Original ResearchConceptsNa,K-ATPaseGamma subunitK-ATPaseSmall membrane proteinsN-linked glycosylationTissue-specific fashionCardiac glycoside bindingGamma subunit mRNAGamma-specific antibodiesNorthern blot analysisHydropathy analysisSequenced proteinsNAB-ouabainMembrane proteinsGamma polypeptidesMolecular cloningGlycoside bindingSmall proteinsNephron segmentsBeta subunitSubunit mRNAAlpha subunitSubunitAmino acidsHydrophobic domains
1987
Rapid release of 42K or 86Rb from two distinct transport sites on the Na,K-pump in the presence of Pi or vanadate.
Forbush B. Rapid release of 42K or 86Rb from two distinct transport sites on the Na,K-pump in the presence of Pi or vanadate. Journal Of Biological Chemistry 1987, 262: 11116-11127. PMID: 2440884, DOI: 10.1016/s0021-9258(18)60933-0.Peer-Reviewed Original ResearchPhysiology and biophysics of chloride and cation cotransport across cell membranes.
Lauf P, McManus T, Haas M, Forbush B, Duhm J, Flatman P, Saier M, Russell J. Physiology and biophysics of chloride and cation cotransport across cell membranes. The FASEB Journal 1987, 46: 2377-94. PMID: 3552736.Peer-Reviewed Original Research
1979
Direct photoaffinity labeling of the primary region of the ouabain binding site of (Na+ + K+)-ATPase with [3H]ouabain, [3H]digitoxin and [3H]digitoxigenin
Forbush B, Hoffman J. Direct photoaffinity labeling of the primary region of the ouabain binding site of (Na+ + K+)-ATPase with [3H]ouabain, [3H]digitoxin and [3H]digitoxigenin. Biochimica Et Biophysica Acta 1979, 555: 299-306. PMID: 224926, DOI: 10.1016/0005-2736(79)90169-x.Peer-Reviewed Original ResearchEvidence that ouabain binds to the same large polypeptide chain of dimeric Na,K-ATPase that is phosphorylated from Pi.
Forbush B, Hoffman J. Evidence that ouabain binds to the same large polypeptide chain of dimeric Na,K-ATPase that is phosphorylated from Pi. Biochemistry 1979, 18: 2308-15. PMID: 221003, DOI: 10.1021/bi00578a027.Peer-Reviewed Original Research
1978
Characterization of a new photoaffinity derivative of ouabain: labeling of the large polypeptide and of a proteolipid component of the Na, K-ATPase.
Forbush B, Kaplan J, Hoffman J. Characterization of a new photoaffinity derivative of ouabain: labeling of the large polypeptide and of a proteolipid component of the Na, K-ATPase. Biochemistry 1978, 17: 3667-76. PMID: 210802, DOI: 10.1021/bi00610a037.Peer-Reviewed Original Research