title: An mRNA encoding a putative GABA-gated chloride channel is expressed in the human cardiac conduction system.
abstract: GABA-gated chloride channels are the main inhibitory neurotransmitter receptors in the CNS. Conserved domains among members of previously described GABAA receptor subunits were used to design degenerate sense and antisense oligonucleotides. A PCR product from this amplification was used to isolate a full-length cDNA. The predicted protein has many of the features shared by other members of the ligand-gated ion channel family. This channel subunit has significant amino acid identity (25-40%) with members of GABAA and GABAC receptor subunits and thus may represent a new subfamily of the GABA receptor channel. Although we cannot rule out that this clone encodes a receptor for an unidentified ligand, it was termed GABA chi. This gene is mainly expressed in placenta and in heart; however, placenta appears to express only an unspliced mRNA. In situ hybridization reveals that the GABA chi subunit mRNA is present in the electrical conduction system of the human heart. Our results suggest that novel GABA receptors expressed outside of the CNS may regulate cardiac function.
authors.affiliation: Laboratoire de Neurophysiologie, Université de Bordeaux 2, France.
authors.forename: M
authors.initials: M
authors.lastname: Garret
authors.forename: L
authors.initials: L
authors.lastname: Bascles
authors.forename: E
authors.initials: E
authors.lastname: Boue-Grabot
authors.forename: P
authors.initials: P
authors.lastname: Sartor
authors.forename: G
authors.initials: G
authors.lastname: Charron
authors.forename: B
authors.initials: B
authors.lastname: Bloch
authors.forename: R F
authors.initials: RF
authors.lastname: Margolskee
mesh_terms: D001483:Base Sequence; D015152:Blotting, Northern; D018118:Chloride Channels / Q000235:genetics*; D018076:DNA, Complementary / Q000032:analysis; D015870:Gene Expression / Q000502:physiology; D006329:Heart Conduction System / Q000737:chemistry*; D006801:Humans; D015640:Ion Channel Gating / Q000502:physiology*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D018079:Receptors, GABA / Q000235:genetics*; D011963:Receptors, GABA-A / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
chemical_list: D018118:Chloride Channels; D018076:DNA, Complementary; C546274:GABRE protein, human; D012333:RNA, Messenger; D018079:Receptors, GABA; D011963:Receptors, GABA-A