Ca2+ permeability of unedited and edited versions of the kainate selective glutamate receptor GluR6.
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.
Egebjerg
J
J
Molecular Neurobiology Laboratory, Salk Institute, La Jolla, CA 92037.
Heinemann
S F
SF
D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002412:Cations / Q000378:metabolism; D002463:Cell Membrane Permeability; D004553:Electric Conductivity; D014644:Genetic Variation; D007473:Ion Channels / Q000378:metabolism*; D008564:Membrane Potentials; D008969:Molecular Sequence Data; D009865:Oocytes / Q000378:metabolism; D017393:RNA Editing; D017470:Receptors, Glutamate / Q000235:genetics* / Q000378:metabolism*; D018092:Kainic Acid Receptors; D014981:Xenopus
D002118:Calcium; D002412:Cations; D007473:Ion Channels; D017470:Receptors, Glutamate; D018092:Kainic Acid Receptors