In the worm Caenorhabditis elegans certain genes are critical for the timed death of a cell during development. How the protein products from these genes regulate one another in vivo is not clear. Chen et al. report that the pro-death protein CED-4 is translocated from the mitochondria (where it colocalizes with the anti-death protein CED-9) to the perinuclear membrane upon receipt of a death signal, such as expression of the pro-death protein EGL-1. The movement of CED-4 to the perinuclar membrane did not depend upon caspases and was a prerequisite for normal death, which suggests that the role of CED-9 may be to sequester CED-4 at the mitochondria until the appropriate developmental time for cell death.
Chen, F., Hersh, B.M., Conradt, B., Zhou, Z., Riemer, D., Gruenbaum, Y., and Horvitz, H.R. (2000) Translocation of C. elegans CED-4 to nuclear membranes during programmed cell death. Science 287: 1485-1489. [Abstract] [Full Text]