New Insights into p53 Signaling and Cancer Cell Response to DNA Damage: Implications for Cancer Therapy

Figure 2

Multiple functions of the p21 tumor suppressor. This protein plays a crucial role in the p53 signaling pathway owing to its ability to inhibit cell cycle progression (e.g., by interacting with PCNA and cyclin/CDK complexes), influence gene expression indirectly, through interfering with DNA methyltransferase (MeTase) activity, and directly, by controlling the transcription of genes involved in senescence and mitosis, down-regulating apoptosis (e.g., through interaction with ASK-1), and positively regulating ATM and p53.