Functional analysis of poly(ADP-ribose)polymerase in Drosophila melanogaster

Poly(ADP-ribose) polymerase (PARP) is conserved in eukaryotes. To analyze t he function of PARP, we isolated and characterized the gene for PARP in Dro sophila melanogaster. The PARP gene consisted of six translatable exons and spanned more than 50 kb. The DNA binding domain is encoded by exons 1-4. A lthough the consensus cleavage site of CED-3 like protease during apoptosis is conserved from human to Xenopus laevis PARPs, it is neither conserved i n the corresponding region of Drosophila nor Sarcophaga peregrina. There ar e two cDNAs species in Drosophila. One cDNA could encode the full length PA RP protein (PARP I), while the other is a truncated cDNA which could encode a partial-length PARP protein (PARP II), which lacks the automodification domain and is possibly produced by alternative splicing. The expression of these two forms of PARP in E. coli demonstrated that while PARP II has the catalytic NAD-binding domain and DNA-binding domain it is enzymatically ina ctive. On the other hand PARP I is active. A deletion mutant of PARP gene c ould grow to the end of embryogenesis but did not grow to the adult fly. Th ese results suggest that the PARP gene plays an important function during t he development of Drosophila.