Endoplasmic reticulum stress and ubiquitin-proteasome system impairment in natural scrapie.

Chronic accumulation of misfolded proteins such as PrP can alter the endoplasmic reticulum homeostasis triggering the unfolded protein response (UPR). In this pathogenic event, the molecular chaperones play an important role. Several reports in humans and animals have suggested that neurodegeneration is related to endoplasmic reticulum stress in diseases caused by the accumulation of misfolded proteins.