Drosophila GABAergic systems: sequence and expression of glutamic acid decarboxylase

J Neurochem. 1990 Mar;54(3):1068-78. doi: 10.1111/j.1471-4159.1990.tb02359.x.


A mammalian glutamic acid decarboxylase (GAD) cDNA probe has been utilized to isolate Drosophila cDNA clones that represent a genomic locus in chromosome region 64A. Deletion analysis indicates that this chromosomal locus encodes an enzymatically active GAD protein. The in vitro translation of cRNA representing a Drosophila cDNA clone yields a 57-kDa protein that can be immunoprecipitated by an anti-GAD antiserum. A GAD-immunoreactive protein of the same size can also be detected in Drosophila head extracts. The nucleotide sequence derived from two overlapping Drosophila cDNA clones predicts a 57,759-dalton protein composed of 510 residues that is 53% identical to mammalian GAD. Sequence comparisons of mammalian and Drosophila GAD identify two highly conserved regions (greater than or equal to 70% identity), one of which encompasses a putative co-factor-binding domain. Transcriptional analyses show that expression of the Drosophila Gad gene commences early in embryonic development (4-8 h) and continues in all later developmental stages. A 3.1-kb class of mRNA is detected throughout embryogenesis, in all three larval stages, in pupae, and in adults. This transcript class has a widespread distribution in the adult CNS. A smaller 2.6-kb transcript is expressed in a developmentally regulated manner; it is detected only in embryos and pupae.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Central Nervous System / metabolism
  • Chromosome Deletion
  • Cloning, Molecular
  • DNA / genetics
  • Dopa Decarboxylase / genetics
  • Drosophila melanogaster / genetics*
  • Drosophila melanogaster / physiology
  • Forecasting
  • Gene Expression Regulation, Enzymologic*
  • Glutamate Decarboxylase / genetics*
  • Glutamate Decarboxylase / metabolism
  • Immunologic Techniques
  • Molecular Sequence Data
  • Protein Biosynthesis
  • RNA / genetics
  • RNA, Complementary
  • Transcription, Genetic
  • gamma-Aminobutyric Acid / physiology*


  • RNA, Complementary
  • gamma-Aminobutyric Acid
  • RNA
  • DNA
  • Dopa Decarboxylase
  • Glutamate Decarboxylase