Drosophila GABAergic systems: sequence and expression of glutamic acid decarboxylase.
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.
Worcester Foundation for Experimental Biology, Shrewsbury, MA 01545.
F R
FR
Jackson
L M
LM
Newby
S J
SJ
Kulkarni
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002490:Central Nervous System / Q000378:metabolism; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D004296:Dopa Decarboxylase / Q000235:genetics; D004331:Drosophila melanogaster / Q000235:genetics* / Q000502:physiology; D005544:Forecasting; D015971:Gene Expression Regulation, Enzymologic; D005968:Glutamate Decarboxylase / Q000235:genetics* / Q000378:metabolism; D007158:Immunologic Techniques; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D012313:RNA / Q000235:genetics; D018075:RNA, Complementary; D014158:Transcription, Genetic; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D018075:RNA, Complementary; D005680:gamma-Aminobutyric Acid; D012313:RNA; D004247:DNA; D004296:Dopa Decarboxylase; D005968:Glutamate Decarboxylase