Characterization of a Plant Glutamate Receptor Activity

Enrico Teardo, Anna Segalla, Elide Formentin, Manuela Zanetti, Oriano Marin, Giorgio M. Giacometti, Fiorella Lo Schiavo, Mario Zoratti, Ildikò Szabò
2010 Cellular Physiology and Biochemistry  
Bioinformatic approaches have allowed the identification of twenty genes, grouped into three subfamilies, encoding for homologues of animal ionotropic glutamate receptors (iGLRs) in the Arabidopsis thaliana model plant. Indirect evidence suggests that plant iGLRs function as non-selective cation channels. In the present work we provide biochemical and electrophysiological evidences for the chloroplast localization of glutamate receptor(s) of family 3 (iGLR3) in spinach. A specific antibody,
more » ... cific antibody, recognizing putative receptors of family 3 locates iGLR3 to the inner envelope membrane of chloroplasts. In planar lipid bilayer experiments, purified inner envelope vesicles from spinach display a cation-selective electrophysiological activity which is inhibited by DNQX (6,7dinitroquinoxaline-2,3-dione), considered to act as an inhibitor on both animal and plant iGLRs. These results identify for the first time the intracellular localization of plant glutamate receptor(s) and a DNQXsensitive, glutamate-gated activity at single channel level in native membrane with properties compatible with those predicted for plant glutamate receptors.
doi:10.1159/000320525 pmid:20798509 fatcat:zjfqci2tbjbsjdyp4nrobwrll4