Atypical functional properties of GluK3-containing kainate receptors
Journal of Neuroscience. 2009-12-09; 29(49): 15499-15510
Lire sur PubMed
1. J Neurosci. 2009 Dec 9;29(49):15499-510. doi: 10.1523/JNEUROSCI.2724-09.2009.
Atypical functional properties of GluK3-containing kainate receptors.
Perrais D(1), Coussen F, Mulle C.
(1)Laboratoire Physiologie Cellulaire de la Synapse, Centre National de la
Recherche Scientifique Unité Mixte de Recherche 5091, Bordeaux Neuroscience
Institute, University of Bordeaux, 33076 Bordeaux, France.
The properties of synaptic receptors determine their mode of action at
presynaptic and postsynaptic loci. Here, we investigated the atypical biophysical
properties of GluK3-containing kainate receptors, which contribute to presynaptic
facilitation at hippocampal mossy fiber synapses. We show, using fast glutamate
applications on outside-out patches and kinetic modeling, that the low
sensitivity of GluK3 receptors for glutamate is attributable to fast
desensitization of partially bound receptors. Consequently, these receptors can
only be activated by fast transients of high glutamate concentration. In
addition, GluK3 receptors are very sensitive to voltage-dependent block by
intracellular spermine that precludes activation of substantial currents at
potentials positive to -50 mV. Two specific residues within the channel pore
define this high-affinity site. Finally, GluK3 are calcium permeable in the same
way as unedited GluK2 receptors. These receptors present unique properties among
AMPA/kainate receptors that could reflect a specialized presynaptic function.
PMID: 20007474 [Indexed for MEDLINE]