Question

The p53 protein can activate genes involved in apoptosis. Review Concept 11.5, and discuss how mutations in genes coding for proteins that function in apoptosis could contribute to cancer.

Short answer

The p53 tumor suppressor genes activate apoptosis. However, a mutation in the p53 genes can suppress the mechanism of apoptosis that leads to a rapid division of cells resulting in cancer.

Step-by-step solution

Description of p53 protein

p53 is the gene that controls cell division and growth. The proteins produced from p53 genes are those involved in the control of the cell cycle mechanisms.

Apoptosis

Every cell tends to divide to maintain the population of new cells. However, cell multiplication has to stop at a certain point, and the cells have to enter the death phase.

The process of cell death is regulated by certain internal body mechanisms called apoptosis, which is otherwise called programmed cell death.

Removal of cells by apoptosis

Cells are exposed to damage frequently, which needs to be removed from the regular cell cycle. These cells enter the apoptotic pathway and get eliminated from the body.

p53 is a gene that activates apoptosis by the transcriptional activation mechanism of the apoptotic protein. It acts as a checkpoint mechanism to eliminate the damaged cells.

Mutation in the P53 gene related to cancer

Mutation in the p53 gene that involves apoptosis can result in the suppression of apoptotic control. The loss in apoptotic control may lead to the rapid multiplication of cells without cell death, which causes the accumulation of cells forming a tumor mass.

It also leads to the growth of damaged or unrepaired cells that result in defective metabolic activities. Thus, a mutation in the p53 gene may block the apoptotic pathway. This may not remove the damaged cell from the cell cycle and eventuallyresult in tumor formation.