How Cells Live or Die

This cell is undergoing apoptosis. © 2001 by the University of Central Arkansas

Scientists have shown that when under stress, cells activate signals that lead to what has been called the "unfolded protein response" or UPR.

This response signals the cell to proceed in one of two pathways. One pathway leads to adaptation, while the other leads to apoptosis or cell death.

The stress is caused by a buildup of improperly folded or non-folded proteins in a cell. This condition is often a result of a genetic defect and can lead to disorders such as Parkinson disease.

In the study, the researchers treated cells with chemicals that did not allow the proteins to fold. They found that at low chemical levels, the cells adapted, the amount of unfolded proteins decreased, and the cells became resistant to further stress. At high chemical levels however, the cells died.

Learn more about this study:

• Apoptosis Versus Survival: When in Doubt, Choose Both (PLoS Biology 4(11): e408)