PIDD: a switch hitter.
In response to genotoxic stress, the PIDD protein promotes apoptosis downstream of the tumor-suppressor protein p53. In this issue of Cell, Janssens et al. (2005) demonstrate that, in response to such stress, PIDD forms a nuclear complex that enhances sumoylation of NEMO. This modification is important for the activation of the antiapoptotic transcription factor NF-kappaB.
Apoptosis↗