Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Proc Natl Acad Sci U S A
2000 Jul 18;9715:8641-6. doi: 10.1073/pnas.97.15.8641.
Show Gene links
Show Anatomy links
Pentameric assembly of a neuronal glutamate transporter.
Eskandari S, Kreman M, Kavanaugh MP, Wright EM, Zampighi GA.
???displayArticle.abstract???
Freeze-fracture electron microscopy was used to study the structure of a human neuronal glutamate transporter (EAAT3). EAAT3 was expressed in Xenopus laevis oocytes, and its function was correlated with the total number of transporters in the plasma membrane of the same cells. Function was assayed as the maximum charge moved in response to a series of transmembrane voltage pulses. The number of transporters in the plasma membrane was determined from the density of a distinct 10-nm freeze-fracture particle, which appeared in the protoplasmic face only after EAAT3 expression. The linear correlation between EAAT3 maximum carrier-mediated charge and the total number of the 10-nm particles suggested that this particle represented functional EAAT3 in the plasma membrane. The cross-sectional area of EAAT3 in the plasma membrane (48 +/- 5 nm(2)) predicted 35 +/- 3 transmembrane alpha-helices in the transporter complex. This information along with secondary structure models (6-10 transmembrane alpha-helices) suggested an oligomeric state for EAAT3. EAAT3 particles were pentagonal in shape in which five domains could be identified. They exhibited fivefold symmetry because they appeared as equilateral pentagons and the angle at the vertices was 110 degrees. Each domain appeared to contribute to an extracellular mass that projects approximately 3 nm into the extracellular space. Projections from all five domains taper toward an axis passing through the center of the pentagon, giving the transporter complex the appearance of a penton-based pyramid. The pentameric structure of EAAT3 offers new insights into its function as both a glutamate transporter and a glutamate-gated chloride channel.
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 Béliveau,
Molecular sizes of amino acid transporters in the luminal membrane from the kidney cortex, estimated by the radiation-inactivation method.
1990,
Pubmed Bergles,
Synaptic activation of glutamate transporters in hippocampal astrocytes.
1997,
Pubmed Billups,
Modulation of non-vesicular glutamate release by pH.
1996,
Pubmed Billups,
Physiological and pathological operation of glutamate transporters.
1998,
Pubmed Branton,
Fracture faces of frozen membranes.
1966,
Pubmed Chandy,
Comparison of the water transporting properties of MIP and AQP1.
1997,
Pubmed
,
Xenbase Conradt,
Localization of N-glycosylation sites and functional role of the carbohydrate units of GLAST-1, a cloned rat brain L-glutamate/L-aspartate transporter.
1995,
Pubmed
,
Xenbase Danbolt,
Properties and localization of glutamate transporters.
1998,
Pubmed Diamond,
Transporters buffer synaptically released glutamate on a submillisecond time scale.
1997,
Pubmed Eskandari,
Thyroid Na+/I- symporter. Mechanism, stoichiometry, and specificity.
1997,
Pubmed
,
Xenbase Eskandari,
Structural analysis of cloned plasma membrane proteins by freeze-fracture electron microscopy.
1998,
Pubmed
,
Xenbase Eskandari,
Number of subunits comprising the epithelial sodium channel.
1999,
Pubmed
,
Xenbase Fairman,
An excitatory amino-acid transporter with properties of a ligand-gated chloride channel.
1995,
Pubmed
,
Xenbase Gaal,
Postsynaptic response kinetics are controlled by a glutamate transporter at cone photoreceptors.
1998,
Pubmed Grunewald,
Biotinylation of single cysteine mutants of the glutamate transporter GLT-1 from rat brain reveals its unusual topology.
1998,
Pubmed Haugeto,
Brain glutamate transporter proteins form homomultimers.
1996,
Pubmed Hediger,
Glutamate transporters in kidney and brain.
1999,
Pubmed Levy,
Stoichiometry of the glial glutamate transporter GLT-1 expressed inducibly in a Chinese hamster ovary cell line selected for low endogenous Na+-dependent glutamate uptake.
1998,
Pubmed Loo,
Conformational changes couple Na+ and glucose transport.
1998,
Pubmed
,
Xenbase Loo,
Relaxation kinetics of the Na+/glucose cotransporter.
1993,
Pubmed
,
Xenbase Masson,
Neurotransmitter transporters in the central nervous system.
1999,
Pubmed Otis,
Postsynaptic glutamate transport at the climbing fiber-Purkinje cell synapse.
1997,
Pubmed
,
Xenbase Otis,
Anion currents and predicted glutamate flux through a neuronal glutamate transporter.
1998,
Pubmed Pinto da Silva,
Membrane splitting in freeze-ethching. Covalently bound ferritin as a membrane marker.
1970,
Pubmed Sahin-Tóth,
Properties of permease dimer, a fusion protein containing two lactose permease molecules from Escherichia coli.
1994,
Pubmed Seal,
A reentrant loop domain in the glutamate carrier EAAT1 participates in substrate binding and translocation.
1998,
Pubmed Seal,
Excitatory amino acid transporters: a family in flux.
1999,
Pubmed Slotboom,
Structural features of the glutamate transporter family.
1999,
Pubmed Slotboom,
Membrane topology of the C-terminal half of the neuronal, glial, and bacterial glutamate transporter family.
1996,
Pubmed van Heel,
A new generation of the IMAGIC image processing system.
1996,
Pubmed Wadiche,
Macroscopic and microscopic properties of a cloned glutamate transporter/chloride channel.
1998,
Pubmed
,
Xenbase Wadiche,
Kinetics of a human glutamate transporter.
1995,
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 Wright,
Regulation of Na+/glucose cotransporters.
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 Zampighi,
Functional and morphological correlates of connexin50 expressed in Xenopus laevis oocytes.
1999,
Pubmed
,
Xenbase Zerangue,
Flux coupling in a neuronal glutamate transporter.
1996,
Pubmed
,
Xenbase
