Cloning, expression and electrophysiological characterization of glycine receptor alpha subunit from zebrafish

• Published in: Neuroscience Vol. 90; no. 1; pp. 303 - 317
• Main Authors: David-Watine, B., Goblet, C., de Saint Jan, D., Fucile, S., Devignot, V., Bregestovski, P., Korn, H.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.02.1999; Elsevier
• Subjects: Amino Acid Sequence; Animals; Base Sequence; Biological and medical sciences; Central nervous system; Central neurotransmission. Neuromudulation. Pathways and receptors; Chromosome Mapping; Cloning, Molecular; Danio rerio; Electrophysiology; Freshwater; Fundamental and applied biological sciences. Psychology; GABA; Gene Expression; glycine receptor; Molecular Sequence Data; oocyte expression; Polymerase Chain Reaction; receptor phylogeny; Receptors, Glycine - genetics; taurine; Vertebrates: nervous system and sense organs; Zebrafish; HEPES, N-2-hydroxyethylpiperazine- N′-2-ethanesulfonic acid; GFP, Green Fluorescent Protein; taurine; oocyte expression; GlyR, glycine receptor; GABA AR, type A GABA receptor; BAPTA, 1,2-bis(2-aminophenoxy)ethane- N, N, N′, N′-tetraacetate; glycine receptor; receptor phylogeny; GABA; PCR, polymerase chain reaction; zebrafish; RACE, rapid amplification of cDNA end; Taurine; Central nervous system; Electrophysiology; Phylogeny; Gene expression; Subunit; Characterization; Vertebrata; Brachydanio rerio; Pisces; Glycine receptor; Molecular cloning; Brain (vertebrata)
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/S0306-4522(98)00430-8

The glycine receptor is a ligand-gated anion channel protein, providing inhibitory drive within the nervous system. We report here the isolation and functional characterization of a novel α subunit ( αZ1) of the glycine receptor from adult zebrafish ( Danio rerio) brain. The predicted amino acid sequence is 86%, 81% and 77% identical with mammalian isoforms α1, α3 and α2, respectively. αZ1 exhibits many of the molecular features of mammalian α1, but the sequence patterns in the M4 and C-terminal domains are more similar to α2/ α3. Phylogenetic analysis indicates that αZ1 is more closely related to the mammalian α1 subunits, being positioned, however, on a distinct branch. The αZ1 messenger RNA is 9.5 kb, similar to that described previously for α1 messenger RNAs. When expressed in Xenopus oocytes or a human cell line (BOSC 23), αZ1 forms a homomeric receptor which is activated by glycine and antagonized by strychnine. This receptor demonstrates unexpectedly high sensitivity to taurine and can also be activated by GABA. These results are consistent with physiological findings in lamprey and goldfish, and they suggest that this teleost fish glycine receptor displays a lower selectivity to neurotransmitters than that reported for glycine mammalian receptors.