Dynamic Homeostasis and Feedback Question 4

The p53 protein regulates a cellular response to DNA damage. Based on the diagram above, which of the following best describes the role of p53 in the response to DNA damage?

Phosphorylated p53 binds to DNA and repairs the damage.

Phosphorylated p53 stimulates transcription of p21, and the resulting p21 protein suppresses cell division until the DNA damage is repaired.

Phosphorylated p53 binds cyclin-Cdk complexes, and the resulting protein complex repairs the DNA damage.

Phosphorylated p53 activates p21 proteins, and the p21 proteins in turn repair the DNA damage.