Question

Which one of the following proteins is often referred to as "the guardian of the genome"?

• A. PFU
• B. Rb
• C. Myc
• D. p53

Hint:

The link between \textbf{p53} and "guardian of the genome" is one of the most famous in molecular cancer biology. Mutations in the TP53 gene (which codes for p53) are found in over 50\% of all human cancers, highlighting its critical role.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
The designation "guardian of the genome" aptly describes a key tumor suppressor protein vital for preserving genetic stability and preventing cancer.
Step 2: Detailed Explanation:


The protein p53, a transcription factor, becomes activated in response to cellular stresses, especially DNA damage.

Once activated, p53 can induce cell cycle arrest, providing time for DNA repair.

If DNA damage is irreparable, p53 initiates apoptosis, eliminating potentially cancerous cells.

By preventing the proliferation of cells with damaged DNA, p53 safeguards genomic integrity and inhibits tumor development, thus earning its title as "the guardian of the genome."

The other options represent different protein types: Rb, another tumor suppressor, regulates the G1/S checkpoint. Myc, a proto-oncogene, stimulates cell proliferation. PFU (plaque-forming unit) is a virology term, not a protein name in this context.

Step 3: Final Answer:
The protein p53 is known as "the guardian of the genome."