Figure 2.
Similarities between RB and p53 in the induction of apoptotic cell death. Both p53 (directly) and RB (with E2F1 or via E2F activity) can increase the transcription of proapoptotic genes in the nucleus. Only some of the known targets are shown, with a focus on genes encoding key apoptotic regulators and common targets between p53 and E2F. Components or regulators of the apoptotic machinery at the mitochondria are highlighted in a box. Note that Puma can disrupt the interaction between p53 and Bcl-XL, thereby allowing p53 to activate Bax and Bak. The new study from Hilgendorf et al. (2013) indicates that RB can also directly control Bax at the mitochondria, similarly to p53, which can activate Bax and Bak at the mitochondrial membrane to promote apoptotic cell death.