HOMOLOGIES AND DISPARITIES OF GLUTAMATE RECEPTORS - A CRITICAL ANALYSIS

Based on analysis of aligned amino acid sequences the following statem ents are made: (i) There is evolutionary homology between the N-termin al extracellular region of ionotropic Glutamate receptors/Kainate Bind ing Proteins and a family of procaryote amino acid binding proteins. ( ii) Homology of the N-terminal extracellular domain of the metabotropi c glutamate receptors with a family of receptors with a guanylate cycl ase intracellular domain appears to be valid. (iii) There is no eviden ce for homology between the N-terminal extracellular domain of the nic otinic Acetylcholine, GABA, Glycine and 5HT3 receptors and that of the ionotropic Glutamate receptors/Kainate Binding proteins. (iv) The pro posal of homology for the N-terminal extracellular domain of metabotro pic Glutamate receptors and that of ionotropic Glutamate receptors doe s not appear to hold.