Solute carrier family 1 (glial high affinity glutamate transporter), member 3
Identifiers
Symbols  ; EA6; EAAT1; GLAST; GLAST1
External IDs ChEMBL: GeneCards:
RNA expression pattern
Orthologs
Species Human Mouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)
RefSeq (protein)
Location (UCSC)
PubMed search

Solute carrier family 1 (glial high-affinity glutamate transporter), member 3, also known as SLC1A3,is a protein that, in humans, is encoded by the SLC1A3 gene.[1] SLC1A3 is also often called the GLutamate ASpartate Transporter (GLAST) or Excitatory Amino Acid Transporter 1 (EAAT1) .

GLAST is predominantly expressed in the plasma membrane, allowing it to remove glutamate from the extracellular space.[2] It has also been localized in the inner mitochondrial membrane as part of the malate-aspartate shuttle.[3]

Mechanism

GLAST functions in vivo as a homotrimer.[4] GLAST mediates the transport of glutamic and aspartic acid with the cotransport of three Na+ and one H+ cations and counter transport of one K+ cation. This co-transport coupling (or symport) allows the transport of glutamate into cells against a concentration gradient.[5]

"Diagram Illustrating the Malate-Asparate Shuttle Pathway". (Glutamate aspartate transporter labeled at bottom center.) 
Expression of SLC1A3 in the Bergmann glia fibers. Mouse brain at 7th postnatal day, sagittal section; GENSAT database. 

Tissue distribution

GLAST is expressed throughout the CNS,[6] and is highly expressed in astrocytes and Bergmann glia in the cerebellum.[7][8] In the retina, GLAST is expressed in Muller cells.[9] GLAST is also expressed in a number of other tissues including cardiac myocytes.[3]

Clinical significance

It is associated with type 6 episodic_ataxia.[10]

Pharmacology

DL-threo-beta-benzyloxyaspartate (TBOA) is an inhibitor of the excitatory amino acid transporters.[11]

Selective inhibitors for GLAST have recently been discovered based on 25 combinations of substitutions at the 4 and 7 positions of 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitril.[12]

References

  1. ^ "Entrez Gene: SLC1A3 solute carrier family 1 (glial high affinity glutamate transporter), member 3". 
  2. ^ Lehre KP, Levy LM, Ottersen OP, Storm-Mathisen J, Danbolt NC (March 1995). "Differential expression of two glial glutamate transporters in the rat brain: quantitative and immunocytochemical observations.". The Journal of neuroscience : the official journal of the Society for Neuroscience 15 (3 Pt 1): 1835–53.  
  3. ^ a b Ralphe JC, Segar JL, Schutte BC, Scholz TD (2004). "Localization and function of the brain excitatory amino acid transporter type 1 in cardiac mitochondria". J. Mol. Cell. Cardiol. 37 (1): 33–41.  
  4. ^ Gendreau S, Voswinkel S, Torres-Salazar D, Lang N, Heidtmann H, Detro-Dassen S, Schmalzing G, Hidalgo P, Fahlke C (Sep 17, 2004). "A trimeric quaternary structure is conserved in bacterial and human glutamate transporters.". The Journal of Biological Chemistry 279 (38): 39505–12.  
  5. ^ Kanai Y, Hediger MA (2004). "The glutamate/neutral amino acid transporter family SLC1: molecular, physiological and pharmacological aspects". Pflugers Arch. 447 (5): 469–79.  
  6. ^ Danbolt NC (September 2001). "Glutamate uptake". Prog. Neurobiol. 65 (1): 1–105.  
  7. ^ Storck T, Schulte S, Hofmann K, Stoffel W (1992). "Structure, expression, and functional analysis of a Na(+)-dependent glutamate/aspartate transporter from rat brain". Proc. Natl. Acad. Sci. U.S.A. 89 (22): 10955–9.  
  8. ^ Rothstein JD, Martin L, Levey AI, Dykes-Hoberg M, Jin L, Wu D, Nash N, Kuncl RW (1994). "Localization of neuronal and glial glutamate transporters". Neuron 13 (3): 713–25.  
  9. ^ Rauen T, Taylor WR, Kuhlbrodt K, Wiessner M (1998). "High-affinity glutamate transporters in the rat retina: a major role of the glial glutamate transporter GLAST-1 in transmitter clearance". Cell Tissue Res. 291 (1): 19–31.  
  10. ^ Jen JC, Wan J, Palos TP, Howard BD, Baloh RW (2005). "Mutation in the glutamate transporter EAAT1 causes episodic ataxia, hemiplegia, and seizures". Neurology 65 (4): 529–34.  
  11. ^ Shimamoto K, Lebrun B, Yasuda-Kamatani Y, Sakaitani M, Shigeri Y, Yumoto N, Nakajima T (February 1998). "DL-threo-beta-benzyloxyaspartate, a potent blocker of excitatory amino acid transporters.". Molecular Pharmacology 53 (2): 195–201.  
  12. ^ Jensen AA, Erichsen MN, Nielsen CW, Stensbøl TB, Kehler J, Bunch L (Feb 26, 2009). "Discovery of the first selective inhibitor of excitatory amino acid transporter subtype 1.". Journal of Medical Chemistry 52 (4): 912–5.  

Further reading

External links