kainate selective glutamate receptor complex

Definition

Target type: cellularcomponent

An assembly of four or five subunits which form a structure with an extracellular N-terminus and a large loop that together form the ligand binding domain. The C-terminus is intracellular. The ionotropic glutamate receptor complex itself acts as a ligand gated ion channel; on binding glutamate, charged ions pass through a channel in the center of the receptor complex. Kainate receptors are multimeric assemblies of GluK1-3 (also called GluR5-7), GluK4 (KA1) and GluK5 (KA2) subunits. [GOC:bf, http://www.bris.ac.uk/Depts/Synaptic/info/glutamate.html, PMID:18655795]

The kainate-selective glutamate receptor complex is a transmembrane protein complex that plays a crucial role in excitatory neurotransmission in the central nervous system. It is composed of multiple subunits, primarily GluK1-GluK5, which assemble into tetrameric structures to form functional ion channels. The cellular component of the kainate receptor complex can be broadly divided into three main domains: the extracellular domain, the transmembrane domain, and the intracellular domain.

**Extracellular Domain:**

- **Ligand-binding domain:** This domain is located at the N-terminus of each subunit and is responsible for binding glutamate, the primary neurotransmitter that activates the receptor. The glutamate binding site is highly specific for kainate, a synthetic analog of glutamate.
- **Dimerization domain:** This domain mediates the interaction between two subunits to form dimers, which are essential for the formation of the tetrameric complex.
- **Glycosylation sites:** The extracellular domain contains glycosylation sites, where sugars are attached to the protein. Glycosylation can influence the trafficking, stability, and activity of the receptor.

**Transmembrane Domain:**

- **Ion channel pore:** This domain forms the central pore of the receptor, which allows the passage of ions across the cell membrane. The pore is selective for cations, primarily sodium and potassium ions.
- **Voltage-sensing domain:** In some kainate receptor subunits, this domain is responsible for detecting changes in membrane potential, which can modulate the activity of the receptor.

**Intracellular Domain:**

- **C-terminus:** This domain is located at the C-terminus of each subunit and contains a variety of binding sites for intracellular signaling proteins. These interactions can influence the phosphorylation, trafficking, and activity of the receptor.
- **PDZ-binding domain:** This domain interacts with PDZ domain-containing proteins, which are involved in protein scaffolding and signaling.
- **Scaffolding proteins:** The intracellular domain can also bind to other scaffolding proteins, which can help to organize and regulate the receptor complex.

The cellular component of the kainate receptor complex is highly dynamic and undergoes a complex series of interactions with other proteins and signaling pathways. This complex interplay contributes to the fine-tuning of neuronal excitability and synaptic plasticity.'
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Proteins (5)

Compounds (20)