Inhibition by lectins of glutamate receptor desensitization is determined by the lectin's sugar specificity at kainate but not AMPA receptors.

The lectin Concanavalin A (ConA) has long been known to potentiate current responses of native and recombinant ionotropic glutamate receptors (iGluRs), apparently by inhibition of receptor desensitization. We compared the effects of a broad range of lectins with different carbohydrate specificities on recombinant AMPA (GluR1) and kainate receptors (GluR6) expressed in Xenopus oocytes. Interestingly, the extent of inhibition of desensitization appears to depend on the sugar preference of lectins at kainate (KA) receptors, but not at alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors.