Author:

Keywords:

Science & Technology, Life Sciences & Biomedicine, Biochemistry & Molecular Biology, endoplasmic reticulum, proteostasis, signalling pathway, stress, UNFOLDED PROTEIN RESPONSE, TO-MESENCHYMAL TRANSITION, PLASMA-CELL DIFFERENTIATION, PANCREATIC BETA-CELLS, BOX-BINDING PROTEIN-1, MESSENGER-RNA DECAY, ER-STRESS, TRANSCRIPTION FACTOR, QUALITY-CONTROL, GLUCOSE-HOMEOSTASIS, Animals, Endoplasmic Reticulum, Endoplasmic Reticulum Stress, Homeostasis, Humans, Signal Transduction, Unfolded Protein Response, 0304 Medicinal and Biomolecular Chemistry, 0601 Biochemistry and Cell Biology, 1101 Medical Biochemistry and Metabolomics, 3101 Biochemistry and cell biology, 3205 Medical biochemistry and metabolomics, 3404 Medicinal and biomolecular chemistry

Abstract:

The endoplasmic reticulum (ER) is a membranous intracellular organelle and the first compartment of the secretory pathway. As such, the ER contributes to the production and folding of approximately one-third of cellular proteins, and is thus inextricably linked to the maintenance of cellular homeostasis and the fine balance between health and disease. Specific ER stress signalling pathways, collectively known as the unfolded protein response (UPR), are required for maintaining ER homeostasis. The UPR is triggered when ER protein folding capacity is overwhelmed by cellular demand and the UPR initially aims to restore ER homeostasis and normal cellular functions. However, if this fails, then the UPR triggers cell death. In this review, we provide a UPR signalling-centric view of ER functions, from the ER's discovery to the latest advancements in the understanding of ER and UPR biology. Our review provides a synthesis of intracellular ER signalling revolving around proteostasis and the UPR, its impact on other organelles and cellular behaviour, its multifaceted and dynamic response to stress and its role in physiology, before finally exploring the potential exploitation of this knowledge to tackle unresolved biological questions and address unmet biomedical needs. Thus, we provide an integrated and global view of existing literature on ER signalling pathways and their use for therapeutic purposes.