Figure 1.

Overview of the initiation of the intrinsic apoptosis pathway. Annotations and domain compositions for N. vectensis (sea anemone), S. purpuratus (sea urchin), and B. floridae (amphioxus) are based on analyses performed in this work, whereas data for C. elegans, D. melanogaster, and Homo sapiens are based on literature [1,2,11]. (Protein and domain lengths are not to scale. In our analysis we noticed a few additional, spurious domains in some CED4/Apaf-1 family members; these are not shown in this diagram.) On the left side, a current view of metazoan phylogeny is shown [13].