unfolded protein response

The unfolded protein response (UPR) is a cellular process activated when the endoplasmic reticulum (ER)—a cell’s protein-folding factory—becomes overwhelmed with misfolded or damaged proteins. To maintain cell health, UPR reduces the production of new proteins, increases the capacity to fold proteins correctly, and removes faulty proteins. If stress persists, UPR can initiate cell repair mechanisms or trigger cell death to prevent damage. Overall, UPR helps cells adapt to stress and maintain proper protein function, which is essential for normal health and response to disease.