Players in the PARP-1 cell-death pathway: JNK1 joins the cast

The nuclear enzyme poly(ADP-ribose) polymerase-1 (PARP-1) triggers a cell-death pathway in which mitochondria play an integral part, but it remains uncertain how PARP-1 activation in the nucleus is signaled to the mitochondria. A recent report by Xu and colleagues suggests that Jun kinase-1, a member of the mitogen-activated protein kinase family, might have a crucial role in this signaling pathway.