G protein-coupled GABA receptor complex

Definition

Target type: cellularcomponent

A protein complex which is capable of G protein-coupled GABA receptor activity. In human, it is usually a heterodimer composed of GABA-B receptor subunits 1 and 2. [GO_REF:0000088, GOC:bhm, GOC:TermGenie, PMID:18790874]

The G protein-coupled GABA receptor complex is a multi-protein assembly that mediates the inhibitory effects of the neurotransmitter GABA. It is comprised of the GABA receptor itself, which is a pentameric ion channel composed of various subunits, and a G protein. The cellular component of this complex can be described as follows:

* **Plasma membrane:** The GABA receptor complex is localized to the plasma membrane of neurons, specifically at synapses. This localization allows it to directly interact with GABA released from presynaptic neurons.

* **Extracellular domain:** The GABA receptor subunits have extracellular domains that bind GABA. This binding triggers a conformational change in the receptor, leading to the opening of its ion channel.

* **Transmembrane domain:** The GABA receptor subunits also have transmembrane domains that span the plasma membrane. These domains are responsible for forming the ion channel pore that allows the passage of chloride ions into the neuron.

* **Cytoplasmic domain:** The GABA receptor subunits have cytoplasmic domains that interact with intracellular signaling molecules, including G proteins.

* **G protein:** The G protein is a heterotrimeric protein that is associated with the cytoplasmic domain of the GABA receptor. Upon activation by the GABA receptor, the G protein dissociates into its alpha, beta, and gamma subunits. The alpha subunit can then activate downstream signaling pathways, ultimately leading to the inhibition of neuronal activity.

* **Scaffolding proteins:** Various scaffolding proteins can associate with the GABA receptor complex, contributing to its stability and localization. These proteins can also link the complex to other signaling pathways, further modulating its function.

The precise composition and organization of the G protein-coupled GABA receptor complex can vary depending on the specific neuronal subtype and the presence of different receptor subunits. However, the fundamental components of this complex, including the GABA receptor, G protein, and associated scaffolding proteins, are essential for its function in mediating GABAergic neurotransmission.'
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Proteins (2)

Compounds (13)