Ubiquitination of P53

P53 is a gene that functions as a tumor suppressor in the human genome. Ubiquitin is a small protein molecule that is present in all cells and functions as a part of the body's waste-disposal system to destroy and eliminate mutated or aberrant cells.

Cellular Suicide

The P53 gene is an important part of human DNA.

P53 genes work to suppress tumor growth by triggering apoptosis, the mechanism that causes a cell to die. Apoptosis is an important mechanism the body employs to stay healthy by eliminating unhealthy or mutated cells.

FAS Receptors

One way apoptosis happens is when P53 genes release proteins that stimulate receptors on the cell surface to trigger apoptosis in the mutated cell. These genes produce proteins 53 kilodaltons in size and so they are called P53 proteins.

Ubiquitin

Ubiquitin plays a role in regulating the amount of P53 proteins in a cell. P53 needs to react quickly in the presence of DNA damage and ubiquitination activity must decrease quickly for the P53 to trigger apoptosis. If this process fails, cancerous cells can grow.

References

• Medicine Net: Definition of Ubiquitin
• University of Kentucky: Apoptosis
• University of Colorado: Ubiquitination, Phosphorylation and Acetylation

Resources

• Nature.com: The Ubiquitin System for Protein Degradation and Some of Its Roles in Cell Division