title: Three Distinct Glutamate Decarboxylase Genes in Vertebrates.
abstract: Gamma-aminobutyric acid (GABA) is a widely conserved signaling molecule that in animals has been adapted as a neurotransmitter. GABA is synthesized from the amino acid glutamate by the action of glutamate decarboxylases (GADs). Two vertebrate genes, GAD1 and GAD2, encode distinct GAD proteins: GAD67 and GAD65, respectively. We have identified a third vertebrate GAD gene, GAD3. This gene is conserved in fishes as well as tetrapods. We analyzed protein sequence, gene structure, synteny, and phylogenetics to identify GAD3 as a homolog of GAD1 and GAD2. Interestingly, we found that GAD3 was lost in the hominid lineage. Because of the importance of GABA as a neurotransmitter, GAD3 may play important roles in vertebrate nervous systems.
authors.affiliation: Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, 94143, USA.
authors.forename: Brian P
authors.initials: BP
authors.lastname: Grone
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA.
authors.forename: Karen P
authors.initials: KP
authors.lastname: Maruska
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D019143:Evolution, Molecular; D005091:Exons; D005968:Glutamate Decarboxylase / Q000235:genetics* / Q000378:metabolism; D007438:Introns; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D014714:Vertebrates / Q000235:genetics*
chemical_list: D005968:Glutamate Decarboxylase