p53 Pathway in DNA Damage Response and Apoptosis - Molecular Mechanism Explained #1730132 (License: Personal Use)

The image depicts a canonical DNA damage response pathway where double-strand breaks activate ATM kinase, which phosphorylates p53 at Ser15 and Ser20 (via Chk2) and stabilizes it by inhibiting HDM2-mediated degradation; concurrent activation of FOXO3 enhances p53 transcriptional activity. Stabilized p53 then upregulates pro-apoptotic genes including BAX, p53AIP1, and PUMA, culminating in programmed cell death. Dashed lines indicate regulatory feedback loops, notably HDM2’s negative regulation of p53.

Used in molecular biology, oncology, and genetics educational resources; ideal for textbook figures, research review articles, or university lecture slides explaining tumor suppressor mechanisms and cellular stress responses.