Ca2+ permeability of unedited and edited versions of the kainate selective glutamate receptor GluR6

Proc Natl Acad Sci U S A. 1993 Jan 15;90(2):755-9. doi: 10.1073/pnas.90.2.755.

Abstract

The Ca2+ permeability of the kainate selective glutamate receptor GluR6 depends on the editing of the RNA (or DNA). The unedited version of GluR6, GluR6Q, encodes a glutamine at position 621 (Q/R site) and exhibits a Ca2+/monovalent ion permeability ratio of 1.2, while the edited version of GluR6, GluR6R, encodes an arginine at position 621 and exhibits a permeability ratio of 0.47. Kainate activation of the GluR6 receptor results in currents that are modulated by extracellular calcium ions. Permeability ratios of other divalent ions indicate that the Q/R site is not the only determinant for divalent ion permeability. The level of editing of the receptor will determine the Ca2+ influx through the GluR6 receptor channels and, consequently, may modulate the synaptic activity.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Calcium / metabolism*
  • Cations / metabolism
  • Cell Membrane Permeability*
  • Electric Conductivity
  • Genetic Variation
  • Ion Channels / metabolism*
  • Membrane Potentials
  • Molecular Sequence Data
  • Oocytes / metabolism
  • RNA Editing*
  • Receptors, Glutamate / genetics*
  • Receptors, Glutamate / metabolism*
  • Receptors, Kainic Acid
  • Xenopus

Substances

  • Cations
  • Ion Channels
  • Receptors, Glutamate
  • Receptors, Kainic Acid
  • Calcium