A Drosophila melanogaster cDNA clone (GH01916) encoding a putative 723-residue long (82 kDa) protein (CG 7415) and displaying 50% identity with mammalian cytosolic dipeptidyl aminopeptidase (DPP) III was func-tionally expressed in Schneider S2 cells. Immunocytochemi-cal studies using anti-(rat liver DPP III) Ig indicated the expression of this putative DPP III at the outer cell mem-brane and into the cytosol of transfected cells.