Glutamate receptors in plants.
Ionotropic glutamate receptors function in animals as glutamate-gated non-selective cation channels. Numerous glutamate receptor-like (GLR) genes have been identified in plant genomes, and plant GLRs are predicted, on the basis of sequence homology, to retain ligand-binding and ion channel activity. Non-selective cation channels are ubiquitous in plant membranes and may function in nutrient uptake, signalling and intra-plant transport. However, there is little evidence for amino acid gating of plant ion channels. Recent evidence suggests that plant GLRs do encode non-selective cation channels, but that these channels are not gated by amino acids. The functional properties of these proteins and their roles in plant physiology remain a mystery. The problems surrounding characterization and assignation of function to plant GLRs are discussed in this Botanical Briefing, and potential roles for GLR proteins as non-selective cation channels involved in metabolic signalling are described.
Davenport
Romola
R
Department of Plant Science, Downing Street, Cambridge CB2 3EA, UK. rjd23@cus.cam.ac.uk
D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D019143:Evolution, Molecular; D008969:Molecular Sequence Data; D010944:Plants / Q000235:genetics / Q000378:metabolism*; D017470:Receptors, Glutamate / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
D017470:Receptors, Glutamate