High impact information on Grd

• The inhibitory glycine receptor is a ligand-gated ion channel protein that occurs in different developmentally regulated isoforms in the mammalian central nervous system [1].
• Other ionotropic receptor subunits (LCCH3 and GRD) form GABA-gated cation channels when heterologously expressed [2].
• The gene (named Grd) that encodes the Drosophila polypeptide has been mapped, by in situ hybridization, to position 75A on the left arm of chromosome 3 [3].
• Analysis of cDNA and genomic DNA reveals that these residues are encoded by an extension of an exon that is equivalent to exon 6 of vertebrate GABAA and glycine receptor genes [3].
• It is interesting that the large amino-terminal, presumed extracellular domain of the GRD protein contains an insertion, between the dicysteine loop and the first putative membrane-spanning domain, of 75 amino acids that is not found in any other ligand-gated chloride-channel subunit [3].

Analytical, diagnostic and therapeutic context of Grd

• A polymerase chain reaction (PCR)-based homology probing strategy was employed to screen Drosophila melanogaster genomic DNA for sequences encoding a conserved amino acid 'signature motif' known to be present in vertebrate GABA receptor and glycine receptor subunit genes [4].
• Molecular cloning of the antagonist-binding subunit of the glycine receptor [5].

References