Poster: Membrane Transport

Abs # 1227: Localization and Functional analysis of the Glutamate Receptor from Small Radish

Presenter:	kang, seock , k_seock@hotmail.com
Authors	kang, seock  (A)   An, Chung Sun  (A)
Affiliations:	(A): School of Biological Sciences
Web Site:	http://plaza.snu.ac.kr/~biology/labh/anlab/index.html

The ionotropic glutamate receptors (iGluRs) function as glutamate-activated ion channels in rapid synaptic transmission in animals. Calcium entry through glutamate receptor channels plays important roles in development and in forms of synaptic plasticity. Recently it is proposed that plant GLRs function as NSCCs, but there are no direct evidences for glutamate gating and localization of these channels. Accordingly, We have isolated and characterized a cDNA encoding glutamate receptor from Small Radish(RsGluR). To determine the subcellular localization of RsGluR, GUS-GFP was fused with the C-terminus of RsGluR (RsGluR::GUS-GFP). The expression of RsGluR::GUS-GFP was ubiquitous on the plasmamembrane of seedlings. We also investigate the glutamate gating of RsGluR using the Fluo-4/AM (Ca²⁺ indicator) in Arabidopsis transformed with RsGluR cDNA. Transgenic Arabidopsis 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.