Tag: Unfolded protein response

ERAD is a central ER quality‑control pathway that recognises misfolded proteins, retrotranslocates them to the cytosol, ubiquitinates them and directs them to the proteasome. By preventing proteotoxic accumulation, ERAD preserves ER homeostasis and supports cellular proteostasis.

PERK is a central ER stress sensor that phosphorylates eIF2α, reduces protein synthesis and activates ATF4‑dependent transcription. Through adaptive and apoptotic signalling, PERK coordinates unfolded protein response pathways that restore proteostasis or eliminate irreparably damaged cells.

IRE1 is the most conserved ER stress sensor, activating XBP1 splicing and RIDD to restore proteostasis. Through its kinase and RNase activities, IRE1 detects misfolded proteins, initiates adaptive signalling and coordinates the unfolded protein response during ER stress.

The unfolded protein response (UPR) is a conserved ER stress pathway that detects misfolded proteins and restores proteostasis. Through IRE1, PERK and ATF6 signalling, cells expand folding capacity, reduce protein load and maintain homeostasis under conditions of ER stress.

Cellular stress responses are adaptive defence mechanisms that protect cells from environmental, metabolic and proteotoxic stress. By activating heat‑shock proteins, unfolded protein responses, antioxidant pathways and autophagy, cells restore homeostasis and maintain functional integrity under adverse conditions.