InterPro domain: IPR044440

This entry represents the periplasmic ligand-binding domain of plant glutamate receptors, which have sequence similarity with animal ionotropic glutamate receptor [ 1 , 2 ]. Interestingly, despite sharing a common structure, GLRs and iGluRs display major sequence divergences, especially in key domains such as the receptor, the pore, and the 'gate'. Electrophysiological characterisation of PpGLR1, AtGLR3.2, and AtGLR3.3 showed their ligand-independent activity, providing evidence for functional differences between iGluRs and at least these specific GLRs [ 3 ]. Animal ionotropic glutamate receptors (iGluRs) function in the nervous system, while plant glutamate receptor-like (GLR) homologues are involved in many plant-specific physiological functions, such as sperm signaling in moss, pollen tube growth, root meristem proliferation, innate immune and wound responses [ 4 ].

1. Phylogenetic and expression analysis of the glutamate-receptor-like gene family in Arabidopsis thaliana. Mol Biol Evol 19, 1066-82
2. The identity of plant glutamate receptors. Science 292, 1486-7
3. Comparing Plant and Animal Glutamate Receptors: Common Traits but Different Fates? J Exp Bot