Glutamate Transporters and Mitochondria: Signaling, Co-compartmentalization, Functional Coupling, and Future Directions.

Glutamate Transporters and Mitochondria: Signaling, Co-compartmentalization, Functional Coupling, and Future Directions.
Neurochem Res. 2020 Jan 30;:
Authors: Robinson MB, Lee ML, DaSilva S
Abstract
In addition to being an amino acid that is incorporated into proteins, glutamate is the most abundant neurotransmitter in the mammalian CNS, the precursor for the inhibitory neurotransmitter γ-aminobutyric acid, and one metabolic step from the tricarboxylic acid cycle intermediate α-ketoglutarate. Extracellular glutamate is cleared by a family of Na+-dependent transporters. These transporters are variably expressed by all cell types in the nervous system, but the bulk of clearance is into astrocytes. GLT-1 and GLAST (also called EAAT2 and EAAT1) mediate this activity and are extremely abundant proteins with their expression enriched in fine astrocyte processes. In this review, we will focus on three topics related to these astrocytic glutamate transporters. First, these transporters co-transport three Na+ ions and a H+ with each molecule of glutamate and counter-transport one K+; they are also coupled to a Cl- conductance. The movement of Na+ is sufficient to cause profound astrocytic depolarization, and the movement of H+ is linked to astrocytic acidification. In addition, the movement of Na+ can trigger the activation of Na+ co-transporters (e.g. Na+-Ca2+ exchangers). We will describe the ways in which these ionic movements have been ...

Source: Neurochemical Research - January 29, 2020 Category: Neuroscience Authors: Robinson MB, Lee ML, DaSilva S Tags: Neurochem Res Source Type: research