MOLECULAR-CLONING OF A DROSOPHILA-MELANOGASTER GENE CODING FOR AN HOMOLOG OF HUMAN CARBOXYPEPTIDASE-E

PCR primers derived from two functional domains of vertebrate carboxyp eptidase E (CPE) were used to generate a probe for screening a size-se lected Drosophila melanogaster genomic library. A sequence representin g about 50% of the expected complete sequence was obtained by translat ion of the two open reading frames present on a 1.6 kb DNA genomic fra gment. This partial sequence, homologous to human CPE, CPM, and CPN, c ontained the conserved arginine and zinc binding domains. Similarities to the human enzymes were found with stretches that were equally dive rgent from the three vertebrate carboxypeptidases. Northern blot analy sis revealed the presence of a 6.9 kb transcript for this gene in Dros ophila embryos. I postulate that insects possess a single protein fulf illing CPE, CPM, and CPN functions. (C) 1994 Wiley-Liss, Inc.