The DNA damage response (DDR) pathway is a complex signaling network that senses DNA lesions and coordinates repair with cell cycle checkpoints. A central node in this pathway is the p53 protein. Upon DNA damage, kinases like ATM and Chk2 phosphorylate and stabilize p53. Active p53 then acts as a transcription factor to induce genes like p21 (a CDK inhibitor), leading to cell cycle arrest (G1/S or G2/M checkpoints) to allow time for repair, or to initiate apoptosis if damage is irreparable. Mutations in p53 or other DDR components are ubiquitous in cancer, allowing cells with genomic instability to proliferate.

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Zambia

• ivwananji siwale – 29 pts

• Visual Pathway Lesions
• Positive and Negative Symptoms
• Hallucinations and Delusions
• Antipsychotic Medications
• Emergency: Environmental Emergencies