GRID2

Glutamate receptor, ionotropic, delta 2, also known as GluD2, GluRδ2, or δ₂, is a protein that in humans is encoded by the GRID2 gene.

δ₂ proteins are subunits that form excitatory ligand-gated ion channels and possess 14-24% sequence homology with AMPA, kainate, and NMDA subunits, but, despite their name, do not actually bind glutamate or various other glutamate agonists. They are considered orphan subunits and their endogenous ligand is unknown. δ₂-containing receptors are selectively/predominantly expressed in Purkinje cells in the cerebellum and play a role in synaptogenesis, synaptic plasticity, and motor coordination, as well as in apoptosis (see below).