Glutamate transporters play important roles in the termination of excitatory neurotransmission and in providing cells throughout the body with glutamate for metabolic purposes.

SLC1A7 (EAAT5) belongs to The SLC1 protein family which contains a range of human and prokaryotic glutamate and aspartate transporters¹. EAAT5 is expressed mainly in photoreceptors and bipolar cells in the retina and is essential for the maintenance of normal excitatory synaptic transmission as it determines the time course of glutamate receptor activation. EAAT5 consists of 3 identical subunits that are functionally coupled to the sodium (Na⁺), potassium (K⁺)-ATPase as part of the same macromolecular complex. The transporter operates via an “alternate access mechanism” whereby the translocation of one molecule of glutamate into the cell is coupled with the inward cotransport with 3Na⁺ and 1H⁺ ions. In turn, the return of the empty carrier to the extracellular side of the plasma membrane is coupled to the export of 1K⁺ ion. In addition, EAAT5, may function as glutamate-gated chloride (Cl⁻) channel, generating an anion current that is not stoichiometrically coupled to the uptake of glutamate².

EAAT5 has been linked to the development of hippocampal sclerosis. Hippocampal sclerosis of aging (HS-Aging) is a causative factor in a large proportion of elderly dementia cases³.