glutamate receptor 3; GluR-3; GluR-C; GluR-K3; glutamate receptor ionotropic, AMPA 3; AMPA-selective glutamate receptor 3 (GRIA3, GLUR3, GLURC)

Function

• ionotropic glutamate receptor
• binding of the excitatory neurotransmitter L-glutamate induces a conformation change, leading to the opening of the cation channel, & thereby converts the chemical signal to an electrical impulse
• the receptor then desensitizes rapidly & enters a transient inactive state, characterized by the presence of bound agonist
• palmitoylated
  • depalmitoylated upon glutamate stimulation
  • Cys-621 palmitoylation leads to Golgi retention & decreased cell surface expression
  • in contrast, Cys-847 palmitoylation does not affect cell surface expression but regulates stimulation- dependent endocytosis (putative)
• interacts with PRKCABP, GRIP1 & GRIP2 (putative)
• binds to PDZ domain of GRIP1 via C-terminal SVKI motif
• receptor binds AMPA (quisqualate) > glutamate > kainate

Structure

• homotetramer or heterotetramer of pore-forming glutamate receptor subunits
• tetramers may be formed by the dimerization of dimers
• belongs to the glutamate-gated ion channel (TC 1.A.10) family

Compartment

• cell membrane
• cell junction, synapse, postsynaptic cell membrane

Alternative splicing

named isoforms=2

Pathology

• defects in GRIA3 are the cause of mental retardation X-linked type 94

Notes

uncertain whether Met-1 or Met-7 is initiator

More general terms

• ionotropic receptor subunit
• phosphoprotein
• glycoprotein

Database

• OMIM: https://mirror.omim.org/entry/300699
• OMIM: https://mirror.omim.org/entry/305915
• UniProt: http://www.uniprot.org/uniprot/P42263.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=2892