What is the unfolded protein response?

Unfolded protein response (UPR) is a critical cellular defense mechanism.

Protein folding occurs in the endoplasmic reticulum (ER). Proper protein folding is crucial for synthesizing proteins that perform their functions correctly. Disruptions in the function of the endoplasmic reticulum can result in unfolded or misfolded proteins. Excessive accumulation of unfolded proteins leads to ER stress.

The unfolded protein response (UPR) is an adaptive signaling pathway that responds to the ER stress. It helps to reduce unfolded protein loan, alleviating ER stress and re-establishing cellular homeostasis. Unfolded protein response is also known as ER stress response.

In case of severe or prolonged ER stress, the unfolded protein response initiates apoptosis or programmed cell death.