Final answer:
The unfolded protein response (UPR) is a cellular stress response mechanism that is activated when there is an accumulation of unfolded or misfolded proteins in the endoplasmic reticulum (ER) of a cell. The UPR helps to restore cellular homeostasis by regulating protein synthesis, promoting protein folding, and degrading misfolded proteins.
Step-by-step explanation:
The unfolded protein response (UPR) is a cellular stress response mechanism that is activated when there is an accumulation of unfolded or misfolded proteins in the endoplasmic reticulum (ER) of a cell. The UPR helps to restore cellular homeostasis by regulating protein synthesis, promoting protein folding, and degrading misfolded proteins. It involves the release of ubiquitins, which are small proteins that target unfolded proteins for degradation in the proteasome. ATP hydrolysis drives the unfolding of the target protein, allowing it to enter the proteasome for degradation.