Tag: ER stress

Disulfide bond formation connects cysteine residues through covalent sulfur–sulfur bonds. Explore disulfide chemistry, protein folding, PDI, redox regulation, detection, mapping, protein engineering, and applications.

Protein disulfide isomerase, commonly abbreviated as PDI, is an important thiol-containing enzyme and molecular chaperone involved in the folding, maturation,…

ATF6 is an ER stress‑responsive transcription factor that enhances protein‑folding capacity and strengthens ER‑associated degradation. After trafficking to the Golgi and undergoing regulated proteolysis, ATF6 activates genes that restore ER proteostasis during unfolded protein accumulation.

ER stress arises when misfolded proteins accumulate in the endoplasmic reticulum, overwhelming its folding capacity. Through IRE1, PERK and ATF6 signalling, the unfolded protein response restores proteostasis, reduces protein load and protects cells from stress‑induced damage.

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 proteostasis network is an integrated system of chaperones, degradation pathways and organelle‑specific quality‑control mechanisms that maintains protein folding, stability and function. By coordinating refolding, repair and degradation, cells prevent proteotoxic stress and preserve homeostasis.

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.