Glutamate aspartate transporter

Solute carrier family 1 (glial high-affinity glutamate transporter), member 3, also known as SLC1A3,is a is_associated_with::protein that, in humans, is encoded by the SLC1A3 is_associated_with::gene. 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. It has also been localized in the is_associated_with::inner mitochondrial membrane as part of the is_associated_with::malate-aspartate shuttle.

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

Tissue distribution
GLAST is expressed throughout the CNS, and is highly expressed in is_associated_with::astrocytes and is_associated_with::Bergmann glia in the is_associated_with::cerebellum. In the retina, GLAST is expressed in is_associated_with::Muller cells. GLAST is also expressed in a number of other tissues including is_associated_with::cardiac myocytes.

Clinical significance
It is associated with type 6 episodic_ataxia.

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

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.