Isolation of the gene encoding the Drosophila melanogaster homolog of the Saccharomyces cerevisiae GCN2 eIF-2alpha kinase.
Genomic and cDNA clones homologous to the yeast GCN2 eIF-2alpha kinase (yGCN2) were isolated from Drosophila melanogaster. The identity of the Drosophila GCN2 (dGCN2) gene is supported by the unique combination of sequence encoding a protein kinase catalytic domain and a domain homologous to histidyl-tRNA synthetase and by the ability of dGCN2 to complement a deletion mutant of the yeast GCN2 gene. Complementation of Deltagcn2 in yeast by dGCN2 depends on the presence of the critical regulatory phosphorylation site (serine 51) of eIF-2alpha. dGCN2 is composed of 10 exons encoding a protein of 1589 amino acids. dGCN2 mRNA is expressed throughout Drosophila development and is particularly abundant at the earliest stages of embryogenesis. The dGCN2 gene was cytogenetically and physically mapped to the right arm of the third chromosome at 100C3 in STS Dm2514. The discovery of GCN2 in higher eukaryotes is somewhat unexpected given the marked differences between the amino acid biosynthetic pathways of yeast vs. Drosophila and other higher eukaryotes. Despite these differences, the presence of GCN2 in Drosophila suggests at least partial conservation from yeast to multicellular organisms of the mechanisms responding to amino acid deprivation.
Olsen
D S
DS
Department of Molecular Biology, Vanderbilt University, Nashville, Tennessee 37235, USA.
Jordan
B
B
Chen
D
D
Wek
R C
RC
Cavener
D R
DR
D000595:Amino Acid Sequence; D000818:Animals; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004268:DNA-Binding Proteins; D004331:Drosophila melanogaster / Q000201:enzymology* / Q000235:genetics*; D005656:Fungal Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D017353:Gene Deletion; D017344:Genes, Insect; D005816:Genetic Complementation Test; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010448:Peptide Initiation Factors / Q000096:biosynthesis / Q000737:chemistry; D010766:Phosphorylation; D016133:Polymerase Chain Reaction; D011494:Protein Kinases / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012694:Serine; D014158:Transcription, Genetic; D019892:eIF-2 Kinase / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D010448:Peptide Initiation Factors; D012333:RNA, Messenger; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D012694:Serine; D011494:Protein Kinases; D019892:eIF-2 Kinase