Identification of a Drosophila prolyl endopeptidase and analysis of its expression.

Prolyl endopeptidases (PEPs) are believed to be involved in the metabolism of neuropeptide hormones (reviewed in Mentlein [1988]). Genes encoding PEPs have been isolated from various species, but their expression patterns during development have not been determined. In this study, we isolated a gene encoding a predicted PEP from the fruitfly Drosophila melanogaster. The gene encodes a predicted 756-amino acid protein having extensive sequence similarity to human PEP. We demonstrated that the Drosophila gene (DPEP) is expressed in a spatially restricted pattern in imaginal discs and the larval brain. Our results suggest a role for DPEP in the regional specification of larval tissues. They also provide a starting point for a genetic analysis of the function of this enzyme during development.