Identification and partial characterization of the enzyme of omega: one of five putative DPP IV genes in Drosophila melanogaster

• Published in: Journal of insect science (Tucson, Ariz.) Ariz.), 2005-11, Vol.5 (26), p.1-25
• Main Authors: Chihara, Carol J., Song, Chunyan, LaMonte, Greg, Fetalvero, Kristina, Hinchman, Kristy, Phan, Helen, Pineda, Mario, Robinson, Kelly, Schneider, Gregory P.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Brain - metabolism; CD26; Cell Membrane; Chromosome Mapping; Cytosol - metabolism; Dipeptidyl Peptidase 4 - genetics; Dipeptidyl Peptidase 4 - metabolism; dipeptidyl peptidase IV; Dipeptidyl-Peptidase IV Inhibitors; Drosophila melanogaster; Drosophila melanogaster - genetics; Drosophila melanogaster - metabolism; Drosophila Proteins - antagonists & inhibitors; Drosophila Proteins - genetics; Drosophila Proteins - metabolism; enzyme compartmentalization; DPPIV; Female; Gene Expression Regulation, Developmental; Gene Expression Regulation, Enzymologic; gene identification; Hydrogen-Ion Concentration; Larva - metabolism; Male; Mutation; omega; Ovary - metabolism; Phylogeny; Testis - metabolism
• ISSN: 1536-2442; 1536-2442
• DOI: 10.1673/1536-2442(2005)5[1:IAPCOT]2.0.CO;2

The omega (ome) gene product is a modifier of larval cuticle protein 5 and its alleles (and duplicates) in the third instar of Drosophila melanogaster. Using deletion mapping the locus mapped to 70F-71A on the left arm of chromosome 3. A homozygote null mutant (ome1) shows a pleiotropic phenotype that affected the size, developmental time of the flies, and the fertility (or perhaps the behavior) of homozygous mutant males. The omega gene was verified as producing a dipeptidyl peptidase IV (DPPIV) by genetic analysis, substrate specificity and pH optimum. The identity of the gene was confirmed as CG32145 (cytology 70F4) in the Celera Database (Berkeley Drosophila Genome Project), which is consistent with its deletion map position. The genomic structure of the gene is described and the decrease in DPPIV activity in the mutant ome1 is shown to be due to the gene CG32145 (omega). The D. melanogaster omega DPPIV enzyme was partially purified and characterized. The exons of the ome1 mutant were sequenced and a base substitution mutation in exon 4 was identified that would yield a truncated protein caused by a stop codon. A preliminary study of the compartmentalization of the omega DPPIV enzyme in several organs is also reported. DPPIV dipeptidyl peptidase IV LCP5 & LCP6 third instar larval cuticle proteins 5 & 6 ome & ome1 omega locus name (CG32145) and mutant allele in D. melanogaster pNA paranotroanilide dipeptidyl peptidase IV third instar larval cuticle proteins 5 & 6 omega locus name (CG32145) and mutant allele in D. melanogaster paranotroanilide