Cloning of a putative high-affinity kainate receptor expressed predominantly in hippocampal CA3 cells

Nature. 1991 Jun 27;351(6329):742-4. doi: 10.1038/351742a0.


Kainic acid is a potent neurotoxin for certain neurons. Its neurotoxicity is thought to be mediated by an excitatory amino-acid-gated ion channel (ionotropic receptor) possessing nanomolar affinity for kainate. Here we describe a new member of the rat excitatory amino-acid receptor gene family, KA-1, that has a 30% sequence similarity with the previously characterized alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor subunits GluR-A to -D. The pharmacological profile of expressed recombinant KA-1 determined in binding experiments with [3H]kainate is different from that of the cloned AMPA receptors and similar to the mammalian high-affinity kainate receptor (kainate greater than quisqualate greater than glutamate much greater than AMPA) with a dissociation constant of about 5 nM for kainate. The selectively high expression of KA-1 messenger RNA in the CA3 region of the hippocampus closely corresponds to autoradiographically located high-affinity kainate binding sites. This correlation, as well as the particular in vivo pattern of neurodegeneration observed on kainate-induced neurotoxicity, suggests that KA-1 participates in receptors mediating the kainate sensitivity of neurons in the central nervous system.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding, Competitive
  • Brain / metabolism
  • Cell Line
  • Cloning, Molecular*
  • Gene Expression*
  • Hippocampus / metabolism*
  • Humans
  • Kainic Acid / metabolism
  • Molecular Sequence Data
  • RNA, Messenger / metabolism
  • Rats
  • Receptors, Kainic Acid
  • Receptors, Neurotransmitter / chemistry
  • Receptors, Neurotransmitter / genetics*
  • Receptors, Neurotransmitter / metabolism
  • Recombinant Proteins / metabolism
  • Sequence Homology, Nucleic Acid
  • Tissue Distribution
  • Transfection


  • RNA, Messenger
  • Receptors, Kainic Acid
  • Receptors, Neurotransmitter
  • Recombinant Proteins
  • Kainic Acid

Associated data

  • GENBANK/X59996