Mono(ADP-ribosyl)ation of DNA by apoptosis-inducing protein, pierisin

The cabbage butterfly contains a potent cytotoxic protein, pierisin-1, and this protein is suggested to be an ADP-ribosylating toxin, Pierisin-1 effectively transferred an ADP-ribosyl group to DNA, but not to protein, as is the case with other bacteria-derived ADP-ribosylating toxins. Several spectral analyses and independent syntheses indicated that the acceptor site for ADP-ribosylation is N-2 of guanine base. Pierisin-1 induced apoptosis in mammalian cells accompanied by a release of cytochrome c and activation of a variety of caspases, and this apoptosis was inhibited by overexpression of Bcl-2. Pierisin-1 would be a novel DNA-damaging protein.