glutamattransportører

Glutamattransportører, also known as excitatory amino acid transporters (EAATs), are a family of integral membrane proteins responsible for the reuptake of glutamate from the extracellular space in the brain. Glutamate is the primary excitatory neurotransmitter in the central nervous system, and its extracellular concentration must be tightly regulated to prevent excitotoxicity. EAATs achieve this by actively transporting glutamate from the synaptic cleft and surrounding neuronal environment into glial cells (primarily astrocytes) or neurons.

There are five known subtypes of EAATs in mammals: EAAT1 (GLAST), EAAT2 (GLT-1), EAAT3 (EAAC1), EAAT4, and EAAT5. These transporters differ in their tissue distribution, expression levels, and substrate affinities. For example, EAAT1 and EAAT2 are predominantly found in astrocytes and are responsible for the majority of glutamate uptake in many brain regions. EAAT3 is expressed mainly on neurons, while EAAT4 and EAAT5 are found in specific neuronal populations and have distinct functional roles.

The transport mechanism of EAATs is dependent on the electrochemical gradients of ions, typically sodium, potassium, and protons. The reuptake of glutamate by EAATs is crucial for synaptic plasticity, learning, memory, and preventing neuronal damage. Dysregulation or dysfunction of glutamate transporters has been implicated in various neurological disorders, including stroke, epilepsy, Alzheimer's disease, and amyotrophic lateral sclerosis (ALS). Therefore, EAATs represent important targets for therapeutic intervention in a range of neurological conditions.