Kainate receptors are found both in the presynaptc terminals and the postsynaptic neurons.
Kainate receptor activation could lead to either ionotropic activity (influx of Ca2+ or Na+ and K+) in the postsynaptic neuron or coupling of the receptor with G proteins in the presynaptic and the postsynaptic neurons.
Kainate receptors are tetramers made from subunits GRIK1-5 or GluR5-7 and KA1-2. Activation of kainate receptors made from GRIK1 or KA2 release Ca2+ from the intracellular stores in a G protein-dependent manner. The G protein involved in this process is sensitive to pertussis toxin.