Cloning of a putative glutamate receptor: a low affinity kainate-binding subunit

Neuron. 1992 Feb;8(2):257-65. doi: 10.1016/0896-6273(92)90292-l.


Kainate, a glutamate receptor agonist, is a potent neuroexcitatory agent that produces epileptiform activity and selective neuronal degeneration. Binding studies using neuronal membrane homogenates or brain sections have identified sites having either high or low affinity for [3H]kainate. Here we report the cloning of a gene, GluR7, with approximately 75% sequence identity with the previously cloned GluR5 and GluR6 subunit genes. Transcripts of the GluR7 gene are evident in brain areas that bind [3H]kainate and are susceptible to kainate-induced neurotoxicity. We have performed ligand binding studies with membranes of transfected HeLa cells expressing GluR6 or GluR7 subunits. Our data show that the GluR6 and GluR7 subunits have a rank order of agonist affinity (domoate greater than kainate much greater than L-glutamate, quisqualate much greater than AMPA, NMDA) and a dissociation constant for kainate (95 and 77 nM, respectively) characteristic of the low affinity kainate-binding sites described in the brain.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Brain / metabolism
  • Brain / ultrastructure
  • Brain Chemistry
  • Cloning, Molecular
  • Female
  • Gene Expression / genetics
  • Glutamates / administration & dosage
  • Glutamates / metabolism
  • Glutamates / pharmacology
  • HeLa Cells
  • Histocytochemistry
  • Humans
  • Injections
  • Kainic Acid / administration & dosage
  • Kainic Acid / analogs & derivatives
  • Kainic Acid / metabolism*
  • Kainic Acid / pharmacology
  • Molecular Sequence Data
  • Nucleic Acid Hybridization
  • Oocytes / chemistry
  • Oocytes / metabolism
  • Oocytes / ultrastructure
  • Protein Binding
  • RNA / genetics
  • Rats
  • Receptors, Glutamate
  • Receptors, Neurotransmitter / analysis
  • Receptors, Neurotransmitter / genetics*
  • Receptors, Neurotransmitter / metabolism
  • Xenopus laevis


  • Glutamates
  • Receptors, Glutamate
  • Receptors, Neurotransmitter
  • RNA
  • domoic acid
  • Kainic Acid

Associated data

  • GENBANK/M83552