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Passive water and urea permeability of a human Na(+)-glutamate cotransporter expressed in Xenopus oocytes.
MacAulay N
,
Gether U
,
Klaeke DA
,
Zeuthen T
.
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The human Na(+)-glutamate transporter (EAAT1) was expressed in Xenopus laevis oocytes. The passive water permeability, L(p), was derived from volume changes of the oocyte induced by changes in the external osmolarity. Oocytes were subjected to two-electrode voltage clamp. In the presence of Na(+), the EAAT1-specific (defined in Discussion) L(p) increased linearly with positive clamp potentials, the L(p) being around 23 % larger at +50 mV than at -50 mV. L-Glutamate increased the EAAT1-specific L(p) by up to 40 %. The K(0.5) for the glutamate-dependent increase was 20 +/- 6 microM, which is similar to the K(0.5) value for glutamate activation of transport. The specific inhibitor DL-threo-beta-benzyloxyaspartate (TBOA) reduced the EAAT1-specific L(p) to 72 %. EAAT1 supported passive fluxes of [(14)C]urea and [(14)C]glycerol. The [(14)C]urea flux was increased in the presence of glutamate. The data suggest that the permeability depends on the conformational equilibrium of the EAAT1. At positive potentials and in the presence of Na(+) and glutamate, the pore is enlarged and water and urea penetrate more readily. The L(p) was larger when measured with urea or glycerol as osmolytes as compared with mannitol. Apparently, the properties of the pore are not uniform along its length. The outer section may accommodate urea and glycerol in an osmotically active form, giving rise to larger water fluxes. The physiological role of EAAT1 for water homeostasis in the central nervous system is discussed.
Arriza,
Functional comparisons of three glutamate transporter subtypes cloned from human motor cortex.
1994, Pubmed,
Xenbase
Arriza,
Functional comparisons of three glutamate transporter subtypes cloned from human motor cortex.
1994,
Pubmed
,
Xenbase
Arriza,
Excitatory amino acid transporter 5, a retinal glutamate transporter coupled to a chloride conductance.
1997,
Pubmed
,
Xenbase
Auger,
Fast removal of synaptic glutamate by postsynaptic transporters.
2000,
Pubmed
Barbour,
Electrogenic glutamate uptake in glial cells is activated by intracellular potassium.
1988,
Pubmed
Borgnia,
Cellular and molecular biology of the aquaporin water channels.
1999,
Pubmed
Brew,
Electrogenic glutamate uptake is a major current carrier in the membrane of axolotl retinal glial cells.
,
Pubmed
Chandy,
Comparison of the water transporting properties of MIP and AQP1.
1997,
Pubmed
,
Xenbase
Chang,
Structure of the MscL homolog from Mycobacterium tuberculosis: a gated mechanosensitive ion channel.
1998,
Pubmed
Chen,
Gliotoxic action of glutamate on cultured astrocytes.
2000,
Pubmed
Collins,
The Hofmeister effect and the behaviour of water at interfaces.
1985,
Pubmed
Conradt,
Functional analysis of the high affinity, Na(+)-dependent glutamate transporter GLAST-1 by site-directed mutagenesis.
1995,
Pubmed
,
Xenbase
Courtenay,
Vapor pressure osmometry studies of osmolyte-protein interactions: implications for the action of osmoprotectants in vivo and for the interpretation of "osmotic stress" experiments in vitro.
2000,
Pubmed
Dawson,
Water transport mechanisms: water movement through lipid bilayers, pores, and plasma membranes.
1988,
Pubmed
Dietzel,
Transient changes in the size of the extracellular space in the sensorimotor cortex of cats in relation to stimulus-induced changes in potassium concentration.
1980,
Pubmed
Doyle,
The structure of the potassium channel: molecular basis of K+ conduction and selectivity.
1998,
Pubmed
Eskandari,
Pentameric assembly of a neuronal glutamate transporter.
2000,
Pubmed
,
Xenbase
Fairman,
An excitatory amino-acid transporter with properties of a ligand-gated chloride channel.
1995,
Pubmed
,
Xenbase
Fischbarg,
Glucose transporters serve as water channels.
1990,
Pubmed
,
Xenbase
Golovanevsky,
The reactivity of the gamma-aminobutyric acid transporter GAT-1 toward sulfhydryl reagents is conformationally sensitive. Identification of a major target residue.
1999,
Pubmed
Grunewald,
Biotinylation of single cysteine mutants of the glutamate transporter GLT-1 from rat brain reveals its unusual topology.
1998,
Pubmed
Hediger,
Homology of the human intestinal Na+/glucose and Escherichia coli Na+/proline cotransporters.
1989,
Pubmed
Hirsch,
Regulation of Na+/glucose cotransporter expression by protein kinases in Xenopus laevis oocytes.
1996,
Pubmed
,
Xenbase
Holthoff,
Directed spatial potassium redistribution in rat neocortex.
2000,
Pubmed
Izumi,
Müller cell swelling, glutamate uptake, and excitotoxic neurodegeneration in the isolated rat retina.
1999,
Pubmed
Jung,
Molecular characterization of an aquaporin cDNA from brain: candidate osmoreceptor and regulator of water balance.
1994,
Pubmed
,
Xenbase
Kanai,
Electrogenic properties of the epithelial and neuronal high affinity glutamate transporter.
1995,
Pubmed
,
Xenbase
Kanai,
Primary structure and functional characterization of a high-affinity glutamate transporter.
1992,
Pubmed
,
Xenbase
Kanner,
Binding order of substrates to the sodium and potassium ion coupled L-glutamic acid transporter from rat brain.
1982,
Pubmed
Klöckner,
Functional properties and substrate specificity of the cloned L-glutamate/L-aspartate transporter GLAST-1 from rat brain expressed in Xenopus oocytes.
1994,
Pubmed
,
Xenbase
Koyama,
Transient treatments with L-glutamate and threo-beta-hydroxyaspartate induce swelling of rat cultured astrocytes.
2000,
Pubmed
Lehre,
Differential expression of two glial glutamate transporters in the rat brain: quantitative and immunocytochemical observations.
1995,
Pubmed
Leung,
Urea transport by cotransporters.
2000,
Pubmed
,
Xenbase
Loike,
Sodium-glucose cotransporters display sodium- and phlorizin-dependent water permeability.
1996,
Pubmed
,
Xenbase
Loo,
Passive water and ion transport by cotransporters.
1999,
Pubmed
,
Xenbase
Loo,
Relaxation kinetics of the Na+/glucose cotransporter.
1993,
Pubmed
,
Xenbase
Loo,
Cotransport of water by the Na+/glucose cotransporter.
1996,
Pubmed
,
Xenbase
Ma,
Generation and phenotype of a transgenic knockout mouse lacking the mercurial-insensitive water channel aquaporin-4.
1997,
Pubmed
MacAulay,
Water transport by the human Na+-coupled glutamate cotransporter expressed in Xenopus oocytes.
2001,
Pubmed
,
Xenbase
Mackenzie,
Relationships between Na+/glucose cotransporter (SGLT1) currents and fluxes.
1998,
Pubmed
,
Xenbase
Manley,
Aquaporin-4 deletion in mice reduces brain edema after acute water intoxication and ischemic stroke.
2000,
Pubmed
Meinild,
The human Na+-glucose cotransporter is a molecular water pump.
1998,
Pubmed
,
Xenbase
Meinild,
Water transport by the renal Na(+)-dicarboxylate cotransporter.
2000,
Pubmed
,
Xenbase
Mitrovic,
Identification of functional domains of the human glutamate transporters EAAT1 and EAAT2.
1998,
Pubmed
,
Xenbase
Miyazawa,
Nicotinic acetylcholine receptor at 4.6 A resolution: transverse tunnels in the channel wall.
1999,
Pubmed
Nayeem,
Quaternary structure of the native GABAA receptor determined by electron microscopic image analysis.
1994,
Pubmed
Nelson,
Hydrogen ion cotransport by the renal brush border glutamate transporter.
1983,
Pubmed
Niermann,
A novel role of vasopressin in the brain: modulation of activity-dependent water flux in the neocortex.
2001,
Pubmed
Otis,
Isolation of current components and partial reaction cycles in the glial glutamate transporter EAAT2.
2000,
Pubmed
Otis,
Anion currents and predicted glutamate flux through a neuronal glutamate transporter.
1998,
Pubmed
Parent,
Electrogenic properties of the cloned Na+/glucose cotransporter: I. Voltage-clamp studies.
1992,
Pubmed
,
Xenbase
Parent,
Electrogenic properties of the cloned Na+/glucose cotransporter: II. A transport model under nonrapid equilibrium conditions.
1992,
Pubmed
Rothstein,
Localization of neuronal and glial glutamate transporters.
1994,
Pubmed
Sankararamakrishnan,
Water-mediated conformational transitions in nicotinic receptor M2 helix bundles: a molecular dynamics study.
1995,
Pubmed
Schneider,
Mechanisms of glial swelling induced by glutamate.
1992,
Pubmed
Sha,
Heterologous expression of the Na(+),K(+)-ATPase gamma subunit in Xenopus oocytes induces an endogenous, voltage-gated large diameter pore.
2001,
Pubmed
,
Xenbase
Shimamoto,
DL-threo-beta-benzyloxyaspartate, a potent blocker of excitatory amino acid transporters.
1998,
Pubmed
,
Xenbase
Slotboom,
A conserved serine-rich stretch in the glutamate transporter family forms a substrate-sensitive reentrant loop.
1999,
Pubmed
Slotboom,
Membrane topology of the C-terminal half of the neuronal, glial, and bacterial glutamate transporter family.
1996,
Pubmed
Slotboom,
Cysteine-scanning mutagenesis reveals a highly amphipathic, pore-lining membrane-spanning helix in the glutamate transporter GltT.
2001,
Pubmed
Slotboom,
The structure of glutamate transporters shows channel-like features.
2001,
Pubmed
Tzounopoulos,
Induction of endogenous channels by high levels of heterologous membrane proteins in Xenopus oocytes.
1995,
Pubmed
,
Xenbase
Valentin,
The transport modifier RS1 is localized at the inner side of the plasma membrane and changes membrane capacitance.
2000,
Pubmed
,
Xenbase
Vandenberg,
Molecular basis for differential inhibition of glutamate transporter subtypes by zinc ions.
1998,
Pubmed
,
Xenbase
Wadiche,
Kinetics of a human glutamate transporter.
1995,
Pubmed
,
Xenbase
Wadiche,
Macroscopic and microscopic properties of a cloned glutamate transporter/chloride channel.
1998,
Pubmed
,
Xenbase
Wadiche,
Ion fluxes associated with excitatory amino acid transport.
1995,
Pubmed
,
Xenbase
Wahle,
Membrane topology of the high-affinity L-glutamate transporter (GLAST-1) of the central nervous system.
1996,
Pubmed
,
Xenbase
Yang,
Urea transporter UT3 functions as an efficient water channel. Direct evidence for a common water/urea pathway.
1998,
Pubmed
,
Xenbase
Yang,
Water and glycerol permeabilities of aquaporins 1-5 and MIP determined quantitatively by expression of epitope-tagged constructs in Xenopus oocytes.
1997,
Pubmed
,
Xenbase
Zampighi,
A method for determining the unitary functional capacity of cloned channels and transporters expressed in Xenopus laevis oocytes.
1995,
Pubmed
,
Xenbase
Zarbiv,
Cysteine scanning of the surroundings of an alkali-ion binding site of the glutamate transporter GLT-1 reveals a conformationally sensitive residue.
1998,
Pubmed
Zerangue,
Flux coupling in a neuronal glutamate transporter.
1996,
Pubmed
,
Xenbase
Zeuthen,
Water transport by the Na+/glucose cotransporter under isotonic conditions.
1997,
Pubmed
,
Xenbase
Zeuthen,
Cotransport of H+, lactate and H2O by membrane proteins in retinal pigment epithelium of bullfrog.
1996,
Pubmed
Zeuthen,
Water permeability of ventricular cell membrane in choroid plexus epithelium from Necturus maculosus.
1991,
Pubmed
Zeuthen,
Cotransport of K+, Cl- and H2O by membrane proteins from choroid plexus epithelium of Necturus maculosus.
1994,
Pubmed
