Poster: Membrane transport

Abs # 172: Localization and functional analysis of the glutamate receptor from small radish

Presenter:	Oh, Chang Jae , ohcj@unitel.co.kr
Authors	Oh, Chang Jae  (A)   Kang, Seock  (A)   Kim, Ho Bang  (A)   An, Chung Sun  (A)
Affiliations:	(A): Department of Biological Sciences, Seoul National University

The ionotropic glutamate receptors (iGluRs) function as glutamate-activated ion channels in rapid synaptic transmission in animals. Calcium entry through the glutamate receptor channels plays important roles in development and forms of synaptic plasticity. Recently it is proposed that plant GluRs function as NSCCs, but there are no direct evidence for glutamate gating and localization of these receptor channels. Accordingly, we have isolated and characterized a cDNA encoding glutamate receptor from small radish (RsGluR). To determine the subcellular localization, GUS-GFP was fused with the C-terminus of RsGluR. The expression of RsGluR::GUS-GFP in transformed Arabidopsis was ubiquitous on plasmamembrane. We also investigate the glutamate gating of RsGluR using the Fluo-4/AM (Ca²⁺ indicator). RsGluR overexpression lines demonstrate increased permeability to Ca²⁺ only in the presence of glutamate. These results support the function of RsGluR as a glutamate gated Ca²⁺ permeable channel, the first direct functional evidence for plant glutamate receptor. Microarray analysis is in progress for the transcriptome analysis in transgenic Arabidopsis overexpressing RsGluR.