gamma-aminobutyric acid:sodium:chloride symporter activity

Definition

Target type: molecularfunction

Enables the transfer of a solute or solutes from one side of a membrane to the other according to the reaction: gamma-aminobutyric acid(out) + Na+(out) + Cl-(out) = gamma-aminobutyric acid(in) + Na+(in) + Cl(in). [PMID:7589472, PMID:7861179]

Gamma-aminobutyric acid (GABA):sodium:chloride symporter activity is a crucial process in the nervous system responsible for the reuptake of GABA, the primary inhibitory neurotransmitter in the brain. This process is critical for maintaining normal brain function and preventing neuronal hyperexcitability.

The GABA:sodium:chloride symporter is a transmembrane protein that facilitates the simultaneous movement of one GABA molecule, two sodium ions (Na+), and one chloride ion (Cl-) across the neuronal membrane. This movement occurs in the same direction, from the synaptic cleft (the space between neurons) into the presynaptic neuron.

The process begins with the binding of GABA to the symporter, which initiates a conformational change in the protein, allowing the entry of sodium and chloride ions. The electrochemical gradient of sodium ions drives the transport of GABA, chloride, and sodium into the neuron. Once inside the neuron, GABA is packaged into vesicles for subsequent release at the synapse.

The reuptake of GABA by this symporter plays a vital role in terminating the inhibitory signal at the synapse. By removing GABA from the synaptic cleft, the symporter prevents prolonged activation of GABA receptors, thus ensuring precise control of neuronal activity.

Several factors can influence the activity of the GABA:sodium:chloride symporter, including the concentration of GABA, sodium, and chloride ions, as well as the presence of specific medications. Drugs that inhibit the activity of this symporter, such as tiagabine, can increase GABA levels in the synaptic cleft, leading to enhanced inhibitory neurotransmission.

In summary, the GABA:sodium:chloride symporter activity is a fundamental process in the nervous system that controls the reuptake of GABA, ensuring proper neuronal inhibition and regulating brain function.'
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Proteins (9)

Compounds (20)