Excitatory amino acid transporter 2
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Location (UCSC) | Chr 11: 35.25 – 35.42 Mb | Chr 2: 102.49 – 102.62 Mb | |||||||
PubMed search | [3] | [4] |
View/Edit Human | View/Edit Mouse |
Excitatory amino acid transporter 2 (EAAT2) also known as solute carrier family 1 member 2 (SLC1A2) and glutamate transporter 1 (GLT-1) is a protein that in humans is encoded by the SLC1A2 gene.[5][6] Alternatively spliced transcript variants of this gene have been described, but their full-length nature is not known.[6]
Function
SLC1A2 / EAAT2 is a member of a family of the solute carrier family of proteins. The membrane-bound protein is the principal transporter that clears the excitatory neurotransmitter glutamate from the extracellular space at synapses in the central nervous system. Glutamate clearance is necessary for proper synaptic activation and to prevent neuronal damage from excessive activation of glutamate receptors.[6] EAAT2 is responsible for over 90% of glutamate reuptake within the brain.[7][8]
Clinical significance
Mutations in and decreased expression of this protein are associated with
Ceftriaxone, an antibiotic, has been shown to induce/enhance the expression of EAAT2, resulting in reduced glutamate activity.[10] Ceftriaxone has been shown to reduce the development and expression of tolerance to opiates and other drugs of abuse. EAAT2 may possess an important role in drug addiction and tolerance to addictive drugs.[11]
Upregulation of EAAT2 (GLT-1) causes impairment of prepulse inhibition, a sensory gating deficit present in schizophrenics and schizophrenia animal models.[12][13] Some antipsychotics have been shown to reduce the expression of EAAT2.[14][15]
Interactions
SLC1A2 has been shown to
As a drug target
EAAT2/GLT-1, being the most abundant subtype of glutamate transporter in the CNS, plays a key role in regulation of glutamate neurotransmission. Dysfunction of EAAT2 has been correlated with various pathologies such as traumatic brain injury, stroke, Amyotrophic lateral sclerosis (ALS), Alzheimer's disease, among others. Therefore, activators of the function or enhancers of the expression of EAAT2/GLT-1 could serve as a potential therapy for these conditions. Translational activators of EAAT2/GLT-1, such as ceftriaxone and LDN/OSU-0212320, have been described to have significant protective effects in animal models of ALS and epilepsy. In addition, pharmacological activators of the activity of EAAT2/GLT-1 have been explored for decades and are currently emerging as promising tools for neuroprotection, having potential advantages over expression activators.[17]
DL-TBOA, WAY-213,613, and dihydrokainic acid are known inhibitors of the protein, and function as excitotoxins. They can be considered a novel class of nerve agent toxins, inducing toxic levels of glutamate through transport inhibition in a manner analogous to the effect of sarin on cholinesterase. Antidotes for such a poisoning have never been formally tested for efficacy and are not readily available for medical use.[18]
Addiction to certain drugs (e.g.,
See also
References
- ^ a b c GRCh38: Ensembl release 89: ENSG00000110436 - Ensembl, May 2017
- ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000005089 - Ensembl, May 2017
- ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
- ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
- S2CID 4243369.
- ^ a b c d "Entrez Gene: SLC1A2 solute carrier family 1 (glial high affinity glutamate transporter), member 2".
- ^ PMID 26635971.
The glutamate transporter 1 (GLT1)/ excitatory amino acid transporter 2 (EAAT2) is responsible for the reuptake of more than 90% glutamate in the CNS [12–14].
- S2CID 41615013.
Since then, a family of five high-affinity glutamate transporters has been characterized that is responsible for the precise regulation of glutamate levels at both synaptic and extrasynaptic sites, although the glutamate transporter 1 (GLT1) is responsible for more than 90% of glutamate uptake in the brain.3 The importance of GLT1 is further highlighted by the large number of neuropsychiatric disorders associated with glutamate-induced neurotoxicity.
Clarification of nomenclature
The major glial glutamate transporter is referred to as GLT1 in the rodent literature and excitatory amino acid transporter 2 (EAAT2) in the human literature. - PMID 22080156.
- PMID 18326497.
- PMID 20634691.
- S2CID 3222131.
- PMID 20072121.
- S2CID 43706291.
- S2CID 18972974.
- S2CID 45768895.
- PMID 26096891.
- PMID 9463476.)
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: CS1 maint: multiple names: authors list (link - ^ PMID 24442756.
Further reading
- Wang Z, Trillo-Pazos G, Kim SY, Canki M, Morgello S, Sharer LR, Gelbard HA, Su ZZ, Kang DC, Brooks AI, Fisher PB, Volsky DJ (2004). "Effects of human immunodeficiency virus type 1 on astrocyte gene expression and function: potential role in neuropathogenesis". J. Neurovirol. 10. 10 (Suppl 1): 25–32. PMID 14982736.
- Arriza JL, Fairman WA, Wadiche JI, Murdoch GH, Kavanaugh MP, Amara SG (1994). "Functional comparisons of three glutamate transporter subtypes cloned from human motor cortex". J. Neurosci. 14 (9): 5559–69. PMID 7521911.
- Manfras BJ, Rudert WA, Trucco M, Boehm BO (1994). "Cloning and characterization of a glutamate transporter cDNA from human brain and pancreas". Biochim. Biophys. Acta. 1195 (1): 185–8. PMID 7522567.
- Li X, Francke U (1995). "Assignment of the gene SLC1A2 coding for the human glutamate transporter EAAT2 to human chromosome 11 bands p13-p12". Cytogenet. Cell Genet. 71 (3): 212–3. PMID 7587378.
- Shashidharan P, Wittenberg I, Plaitakis A (1994). "Molecular cloning of human brain glutamate/aspartate transporter II". Biochim. Biophys. Acta. 1191 (2): 393–6. PMID 8172925.
- Andersson B, Wentland MA, Ricafrente JY, Liu W, Gibbs RA (1996). "A "double adaptor" method for improved shotgun library construction". Anal. Biochem. 236 (1): 107–13. PMID 8619474.
- Yu W, Andersson B, Worley KC, Muzny DM, Ding Y, Liu W, Ricafrente JY, Wentland MA, Lennon G, Gibbs RA (1997). "Large-scale concatenation cDNA sequencing". Genome Res. 7 (4): 353–8. PMID 9110174.
- Milton ID, Banner SJ, Ince PG, Piggott NH, Fray AE, Thatcher N, Horne CH, Shaw PJ (1997). "Expression of the glial glutamate transporter EAAT2 in the human CNS: an immunohistochemical study". Brain Res. Mol. Brain Res. 52 (1): 17–31. PMID 9450673.
- Shimamoto K, Lebrun B, Yasuda-Kamatani Y, Sakaitani M, Shigeri Y, Yumoto N, Nakajima T (1998). "DL-threo-beta-benzyloxyaspartate, a potent blocker of excitatory amino acid transporters". Mol. Pharmacol. 53 (2): 195–201. PMID 9463476.
- Lin CL, Bristol LA, Jin L, Dykes-Hoberg M, Crawford T, Clawson L, Rothstein JD (1998). "Aberrant RNA processing in a neurodegenerative disease: the cause for absent EAAT2, a glutamate transporter, in amyotrophic lateral sclerosis". Neuron. 20 (3): 589–602. PMID 9539131.
- Aoki M, Lin CL, Rothstein JD, Geller BA, Hosler BA, Munsat TL, Horvitz HR, Brown RH (1998). "Mutations in the glutamate transporter EAAT2 gene do not cause abnormal EAAT2 transcripts in amyotrophic lateral sclerosis". Ann. Neurol. 43 (5): 645–53. S2CID 10885891.
- Trotti D, Aoki M, Pasinelli P, Berger UV, Danbolt NC, Brown RH, Hediger MA (2001). "Amyotrophic lateral sclerosis-linked glutamate transporter mutant has impaired glutamate clearance capacity". J. Biol. Chem. 276 (1): 576–82. PMID 11031254.
- Münch C, Schwalenstöcker B, Hermann C, Cirovic S, Stamm S, Ludolph A, Meyer T (2000). "Differential RNA cleavage and polyadenylation of the glutamate transporter EAAT2 in the human brain". Brain Res. Mol. Brain Res. 80 (2): 244–51. PMID 11038258.
- Honig LS, Chambliss DD, Bigio EH, Carroll SL, Elliott JL (2000). "Glutamate transporter EAAT2 splice variants occur not only in ALS, but also in AD and controls". Neurology. 55 (8): 1082–8. S2CID 26759254.
- Flowers JM, Powell JF, Leigh PN, Andersen P, Shaw CE (2001). "Intron 7 retention and exon 9 skipping EAAT2 mRNA variants are not associated with amyotrophic lateral sclerosis". Ann. Neurol. 49 (5): 643–9. S2CID 25451450.
- Rimaniol AC, Mialocq P, Clayette P, Dormont D, Gras G (2001). "Role of glutamate transporters in the regulation of glutathione levels in human macrophages". Am. J. Physiol., Cell Physiol. 281 (6): C1964-70. S2CID 3173417.
- Tozaki H, Kanno T, Nomura T, Kondoh T, Kodama N, Saito N, Aihara H, Nagata T, Matsumoto S, Ohta K, Nagai K, Yajima Y, Nishizaki T (2001). "Role of glial glutamate transporters in the facilitatory action of FK960 on hippocampal neurotransmission". Brain Res. Mol. Brain Res. 97 (1): 7–12. PMID 11744157.
- Palmada M, Kinne-Saffran E, Centelles JJ, Kinne RK (2002). "Benzodiazepines differently modulate EAAT1/GLAST and EAAT2/GLT1 glutamate transporters expressed in CHO cells". Neurochem. Int. 40 (4): 321–6. S2CID 23624873.
- Marie H, Billups D, Bedford FK, Dumoulin A, Goyal RK, Longmore GD, Moss SJ, Attwell D (2002). "The amino terminus of the glial glutamate transporter GLT-1 interacts with the LIM protein Ajuba". Mol. Cell. Neurosci. 19 (2): 152–64. S2CID 45768895.
- Reye P, Sullivan R, Fletcher EL, Pow DV (2002). "Distribution of two splice variants of the glutamate transporter GLT1 in the retinas of humans, monkeys, rabbits, rats, cats, and chickens". J. Comp. Neurol. 445 (1): 1–12. S2CID 23382118.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.