ced-9, a member of the
bcl-2 gene family in Caenorhabditis elegans plays a central roles in preventing cell death in worms. Overexpression of human
bcl-2 can partially prevent cell death in C. elegans. However, it remains to be elucidated whether
ced-9 can regulate cell death when expressed in other organisms. We demonstrated that the CED-9 protein is co-localized with BCL-2 in COS cells and Drosophila Schneider's L2 (SL2) cells, suggesting that the site of CED-9 action is located to specific cytoplasmic compartments. Overexpression of
ced-9 only poorly protected cells from the death induced by
ced-3 in HeLa cells, but
ced-9 significantly reduced the cell death induced by
ced-3 in Drosophila SL2 cells. Furthermore, apoptosis of SL2 cells that was induced by a Drosophila cell-death gene, reaper, was shown to be partially prevented by
ced-9,
bcl-2 and bcl-xL. These results suggest that the signaling pathway that is required for the anti-apoptotic function of
bcl-2 family members, including
ced-9, is conserved in Drosophila cells. In addition, SL2 cells provide a unique systems for dissecting the main machinery of cell death.