GRIK2

Glutamate receptor, ionotropic kainate 2 is a protein that in humans is encoded by the GRIK2 gene.

Function

This gene encodes a subunit of a kainate glutamate receptor. Glutamate receptors mediate the majority of excitatory neurotransmission in the brain. This receptor may have a role in synaptic plasticity and may be important for learning and memory. It also may be involved in the transmission of light information from the retina to the hypothalamus. The structure and function of the encoded protein is changed by RNA editing. Alternatively spliced transcript variants encoding distinct isoforms have been described for this gene.

Clinical significance

Homozygosity for a GRIK2 deletion-inversion mutation is associated with nonsyndromic autosomal recessive mental retardation.

Interactions

GRIK2 has been shown to interact with:

RNA Editing

Several ion channels and neurotransmitters receptors pre-mRNA as substrates for ADARs. This includes 5 subunits of the glutamate receptor ionotropic AMPA glutamate receptor subunits (Glur2, Glur3, Glur4) and kainate receptor subunits (Glur5, Glur6). Glutamate gated ion channels are made up of four subunits per channel with each subunit contributing to the pore loop structure. The pore loop structure is related to that found in K⁺ channels (e.g. human K_v1.1 channel). The human K_v1.1 channel pre mRNA is also subject to A to I RNA editing. The function of the glutamate receptors is in the mediation of fast neurotransmission to the brain. The diversity of the subunits is determined, as well as RNA splicing by RNA editing events of the individual subunits. This give rise to the necessarily high diversity of these receptors. Glur2 is a gene product of the pre- mRNA of the GRIK2 gene is subject to RNA editing.