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Pflugers Arch
2008 Feb 01;4555:885-93. doi: 10.1007/s00424-007-0351-y.
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The sodium-bicarbonate cotransporter NBCe1 supports glutamine efflux via SNAT3 (SLC38A3) co-expressed in Xenopus oocytes.
Wendel C
,
Becker HM
,
Deitmer JW
.
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The glutamine transporter SNAT3 contributes to the glutamine fluxes in liver, kidney, and brain. We heterologously co-expressed SNAT3 with the electrogenic sodium-bicarbonate cotransporter NBCe1 in Xenopus laevis oocytes and measured cytosolic pH and membrane current in voltage clamp. Because of the increased buffer capacity contributed by the NBCe1 (Becker and Deitmer in J Biol Chem 279:28057-28062, 2004), we hypothesized that this may enhance the proton-coupled glutamine transport via SNAT3 in the presence of CO2/HCO3-. Addition and removal of glutamine activated not only SNAT3 but also NBCe1, as indicated by the increased membrane current. The NBCe1 current during glutamine removal was more than 50% larger than during glutamine addition, suggesting that NBCe1 enhances glutamine efflux rather than glutamine uptake. This was confirmed by radio-labeled glutamine flux measurements; influx of glutamine was significantly decreased, whereas efflux of glutamine was increased when SNAT3 was co-expressed with NBCe1. A model is presented that attempts to explain the role of intracellular pH, bicarbonate transport, and buffering capacity mediated by NBCe1 for uptake and efflux of glutamine via SNAT3.
Bak,
The glutamate/GABA-glutamine cycle: aspects of transport, neurotransmitter homeostasis and ammonia transfer.
2006, Pubmed
Bak,
The glutamate/GABA-glutamine cycle: aspects of transport, neurotransmitter homeostasis and ammonia transfer.
2006,
Pubmed
Becker,
Voltage dependence of H+ buffering mediated by sodium bicarbonate cotransport expressed in Xenopus oocytes.
2004,
Pubmed
,
Xenbase
Becker,
Carbonic anhydrase II increases the activity of the human electrogenic Na+/HCO3- cotransporter.
2007,
Pubmed
,
Xenbase
Becker,
Facilitated lactate transport by MCT1 when coexpressed with the sodium bicarbonate cotransporter (NBC) in Xenopus oocytes.
2004,
Pubmed
,
Xenbase
Bevensee,
Intracellular pH regulation in cultured astrocytes from rat hippocampus. II. Electrogenic Na/HCO3 cotransport.
1997,
Pubmed
Brune,
Evidence for electrogenic sodium-bicarbonate cotransport in cultured rat cerebellar astrocytes.
1994,
Pubmed
Bröer,
Characterization of the monocarboxylate transporter 1 expressed in Xenopus laevis oocytes by changes in cytosolic pH.
1998,
Pubmed
,
Xenbase
Bröer,
Regulation of the glutamine transporter SN1 by extracellular pH and intracellular sodium ions.
2002,
Pubmed
,
Xenbase
Chaudhry,
Coupled and uncoupled proton movement by amino acid transport system N.
2001,
Pubmed
,
Xenbase
Chaudhry,
Molecular analysis of system N suggests novel physiological roles in nitrogen metabolism and synaptic transmission.
1999,
Pubmed
Choi,
Cloning and characterization of a human electrogenic Na+-HCO-3 cotransporter isoform (hhNBC).
1999,
Pubmed
,
Xenbase
Deitmer,
Electrogenic sodium-dependent bicarbonate secretion by glial cells of the leech central nervous system.
1991,
Pubmed
Deitmer,
Glutamine efflux from astrocytes is mediated by multiple pathways.
2003,
Pubmed
,
Xenbase
Deitmer,
pH regulation and proton signalling by glial cells.
1996,
Pubmed
Fei,
Primary structure, genomic organization, and functional and electrogenic characteristics of human system N 1, a Na+- and H+-coupled glutamine transporter.
2000,
Pubmed
,
Xenbase
Häussinger,
Liver regulation of acid-base balance.
1997,
Pubmed
Karinch,
Regulation of expression of the SN1 transporter during renal adaptation to chronic metabolic acidosis in rats.
2002,
Pubmed
Karinch,
Glucocorticoids have a role in renal cortical expression of the SNAT3 glutamine transporter during chronic metabolic acidosis.
2007,
Pubmed
Liang,
Dynamic regulation of synaptic GABA release by the glutamate-glutamine cycle in hippocampal area CA1.
2006,
Pubmed
Mackenzie,
Sodium-coupled neutral amino acid (System N/A) transporters of the SLC38 gene family.
2004,
Pubmed
Moret,
Regulation of renal amino acid transporters during metabolic acidosis.
2007,
Pubmed
Mujais,
Tubular CO2 production from glutamine in the rat: segmental profile and modulation.
1992,
Pubmed
Rae,
Inhibition of glutamine transport depletes glutamate and GABA neurotransmitter pools: further evidence for metabolic compartmentation.
2003,
Pubmed
Romero,
Molecular pathophysiology of SLC4 bicarbonate transporters.
2005,
Pubmed
Romero,
Electrogenic Na+/HCO3- cotransporters: cloning and physiology.
1999,
Pubmed
Schneider,
Heterologous expression of the glutamine transporter SNAT3 in Xenopus oocytes is associated with four modes of uncoupled transport.
2007,
Pubmed
,
Xenbase
Tapiero,
II. Glutamine and glutamate.
2002,
Pubmed
