L-glutamate transmembrane transport

Definition

Target type: biologicalprocess

The directed movement of L-glutamate across a membrane by means of some agent such as a transporter or a pore. [PMID:21307582]

L-glutamate transmembrane transport is a crucial process for neuronal function, enabling the movement of glutamate across cell membranes. Glutamate, the primary excitatory neurotransmitter in the central nervous system, plays a pivotal role in synaptic transmission, learning, and memory. The transport of glutamate is mediated by specialized membrane proteins called glutamate transporters. These transporters exhibit high affinity for glutamate and facilitate its movement across the plasma membrane in a tightly regulated manner. There are five main types of glutamate transporters in mammals: EAAT1 (glial glutamate transporter-1), EAAT2 (glial glutamate transporter-2), EAAT3 (neuronal glutamate transporter), EAAT4 (neuronal glutamate transporter), and EAAT5 (neuronal glutamate transporter). These transporters have distinct localization patterns and roles in the nervous system. EAAT1 and EAAT2 are predominantly expressed in astrocytes, the non-neuronal cells that support neuronal function. They play a critical role in removing glutamate from the synaptic cleft after neurotransmission, thus preventing excessive accumulation and excitotoxicity. EAAT3, EAAT4, and EAAT5 are primarily found in neurons and contribute to glutamate uptake at both presynaptic and postsynaptic sites. They regulate glutamate levels and contribute to synaptic plasticity, the ability of synapses to strengthen or weaken over time. The mechanism of glutamate transport involves a series of conformational changes within the transporter protein. The transporter alternates between two main conformations: an inward-facing conformation, where the binding site for glutamate is exposed to the intracellular environment, and an outward-facing conformation, where the binding site is exposed to the extracellular environment. Glutamate binds to the transporter in the inward-facing conformation, triggering a conformational change that exposes the binding site to the extracellular environment. Glutamate is then released from the transporter into the extracellular space, where it can bind to glutamate receptors and trigger neuronal excitation. The transport of glutamate is an active process, meaning it requires energy in the form of ATP. The transporter uses the energy derived from ATP hydrolysis to move glutamate against its concentration gradient, from an area of low concentration to an area of high concentration. This is essential for maintaining the correct glutamate concentration in the synaptic cleft and ensuring efficient neurotransmission.'
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Proteins (5)

Compounds (32)