p53 Mutation Worksheet
By the end of this activity, you should be able to:
1. Distinguish between the different types of point mutations that can occur in DNA.
2. Generate an amino acid sequence from a given DNA sequence using knowledge of transcription and
translation.
Before you start completing the activity, make sure you already have read the activity instructions on Canvas.
The TP53 gene codes for a transcription factor that activates the expression of genes leading to cell cycle arrest.
Expression of the TP53 gene is induced when DNA is damaged. The p53 protein produced works at the G1 cell
cycle checkpoint. Action of p53 prevents progression from G1 to the S phase of the cell cycle until the DNA
damage is repaired. p53 activates the transcription of DNA repair genes. If the damage is repaired, a cell may
later proceed through the cell cycle. If the DNA damage is too severe, p53 activates other genes that promote
programmed cell death or apoptosis. About 50% of all human cancers and 80% of lung cancers are associated
with mutations in the TP53 gene. We will learn about one such mutation below.
