Neuronal and glial glutamate transporters possess an SH-based redox regulatory mechanism
- PMID: 9215707
- DOI: 10.1111/j.1460-9568.1997.tb01478.x
Neuronal and glial glutamate transporters possess an SH-based redox regulatory mechanism
Abstract
Glutamate uptake into nerve cells and astrocytes via high-affinity transporters controls the extracellular glutamate concentration in the brain, with major implications for physiological excitatory neurotransmission and the prevention of excitotoxicity. We report here that three recently cloned rat glutamate transporter subtypes, viz. EAAC1 (neuronal), GLT1 and GLAST (glial), possess a redox-sensing property, undergoing opposite functional changes in response to oxidation or reduction of reactive sulphydryls present in their structure. In particular, thiol oxidation with 5,5'-dithio-bis(2-nitrobenzoic) acid (DTNB) and disulphide reduction with dithiothreitol (DTT) result, respectively, in reduced and increased uptake capacity by a preparation of partially purified brain transporters as well as by the three recombinant proteins reconstituted into liposomes. In this model system, EAAC1, GLT1 and GLAST react similarly to DTT/DTNB exposures despite their different contents of cysteines, suggesting that only the conserved residues might be involved in redox modulation. Redox sensitivity is a property of the glutamate transporters also when present in their native cell environment. Thus, by using cultured cortical astrocytes and the whole-cell patch-clamp technique we were able to observe dynamic increase and decrease of the glutamate uptake current in response to application of DTT and DTNB in sequence. Moreover, in the same paradigm, DDT-reversible current inhibition was observed with hydrogen peroxide instead of DTNB, indicating that the SH-based redox modulatory site is targeted by endogenous oxidants and might constitute an important physiological or pathophysiological regulatory mechanism of glutamate uptake in vivo.
Similar articles
-
Differential modulation of the uptake currents by redox interconversion of cysteine residues in the human neuronal glutamate transporter EAAC1.Eur J Neurosci. 1997 Oct;9(10):2207-12. doi: 10.1111/j.1460-9568.1997.tb01388.x. Eur J Neurosci. 1997. PMID: 9421181
-
Modulation of glutamate transporters (GLAST, GLT-1 and EAAC1) in the rat cerebellum following portocaval anastomosis.Brain Res. 2000 Mar 24;859(2):293-302. doi: 10.1016/s0006-8993(00)01993-4. Brain Res. 2000. PMID: 10719077
-
Comparison of Na+-dependent glutamate transport activity in synaptosomes, C6 glioma, and Xenopus oocytes expressing excitatory amino acid carrier 1 (EAAC1).Mol Pharmacol. 1996 Mar;49(3):465-73. Mol Pharmacol. 1996. PMID: 8643086
-
Glial transporters for glutamate, glycine and GABA I. Glutamate transporters.J Neurosci Res. 2001 Mar 15;63(6):453-60. doi: 10.1002/jnr.1039. J Neurosci Res. 2001. PMID: 11241580 Review.
-
Glial transporters for glutamate, glycine, and GABA III. Glycine transporters.J Neurosci Res. 2001 May 1;64(3):218-22. doi: 10.1002/jnr.1069. J Neurosci Res. 2001. PMID: 11319765 Review.
Cited by
-
Altered glutamate clearance in ascorbate deficient mice increases seizure susceptibility and contributes to cognitive impairment in APP/PSEN1 mice.Neurobiol Aging. 2018 Nov;71:241-254. doi: 10.1016/j.neurobiolaging.2018.08.002. Epub 2018 Aug 7. Neurobiol Aging. 2018. PMID: 30172223 Free PMC article.
-
Assessment of the relative contribution of COX-1 and COX-2 isoforms to ischemia-induced oxidative damage and neurodegeneration following transient global cerebral ischemia.J Neurochem. 2003 Aug;86(3):545-55. doi: 10.1046/j.1471-4159.2003.01812.x. J Neurochem. 2003. PMID: 12859668 Free PMC article.
-
Glutathione in Cellular Redox Homeostasis: Association with the Excitatory Amino Acid Carrier 1 (EAAC1).Molecules. 2015 May 14;20(5):8742-58. doi: 10.3390/molecules20058742. Molecules. 2015. PMID: 26007177 Free PMC article. Review.
-
Sustained Energy Deficit Following Perinatal Asphyxia: A Shift towards the Fructose-2,6-bisphosphatase (TIGAR)-Dependent Pentose Phosphate Pathway and Postnatal Development.Antioxidants (Basel). 2021 Dec 29;11(1):74. doi: 10.3390/antiox11010074. Antioxidants (Basel). 2021. PMID: 35052577 Free PMC article. Review.
-
Activity-Dependent Plasticity of Astroglial Potassium and Glutamate Clearance.Neural Plast. 2015;2015:109106. doi: 10.1155/2015/109106. Epub 2015 Aug 4. Neural Plast. 2015. PMID: 26346563 Free PMC article. Review.
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Miscellaneous