Related Experiment Video
Updated: Nov 3, 2025
10:36
Measurements of Physiological Stress Responses in C. Elegans
Published on: May 21, 2020
14.4K
Evolution and function of the epithelial cell-specific ER stress sensor IRE1β.
Eva Cloots1,2,3,4, Mariska S Simpson5,6, Clint De Nolf3,4
1VIB Center for Medical Biotechnology, Ghent, Belgium.
Mucosal Immunology
|June 2, 2021
Summary
Inositol-requiring enzyme 1β (IRE1β) is crucial for mucosal tissue homeostasis. This enzyme, distinct from IRE1α, plays a key role in the development and physiology of gastrointestinal and respiratory tracts.
Area of Science:
- Cell Biology
- Immunology
- Molecular Biology
Background:
- Barrier epithelial cells in the GI and respiratory tracts maintain host defense against environmental challenges.
- A mucus barrier produced by the epithelium is central to mucosal homeostasis.
- Specific molecules expressed in mucosal epithelia regulate tissue equilibrium.
Purpose of the Study:
- To review the biology of Inositol-requiring enzyme 1β (IRE1β).
- To understand the unique functions of IRE1β in mucosal tissues.
- To explore IRE1β's role in the development and physiology of mucosal tissues.
Main Methods:
- Literature review of IRE1β biology.
- Comparative analysis of IRE1β and IRE1α functions.
- Examination of evolutionary origins of IRE1β.
Main Results:
- IRE1β is an ER-resident endonuclease and paralogue of IRE1α.
- IRE1β evolved through gene duplication in early vertebrates.
- IRE1β possesses functions distinct from IRE1α, essential for mucosal tissues.
Conclusions:
- IRE1β plays a fundamental role in mucosal tissue development and physiology.
- Understanding IRE1β offers insights into maintaining mucosal homeostasis.
- IRE1β represents a key target for studying mucosal immunity and tolerance.
Related Concept Videos
01:31Regulation of the Unfolded Protein Response
2.7K
Inositol-requiring kinase one or IRE1 is the most conserved eukaryotic unfolded protein response (UPR) receptor. It is a type I transmembrane protein kinase receptor with a distinctive site-specific RNase activity. As the binding mechanics of the misfolded proteins with the N-terminal domain of IRE-1 are unclear, three binding models — direct, indirect, and allosteric -- are proposed for receptor activation. Nevertheless, it is known that once a misfolded protein associates with IRE1, it...
2.7K
01:37The Unfolded Protein Response
5.6K
The ER is the hub of protein synthesis in a cell. It has robust systems to quality control protein folding and also for degradation of terminally misfolded proteins. Under normal conditions, a small proportion of misfolded proteins that cannot be salvaged need to be transported to the cytoplasm by the ER-associated degradation or ERAD pathways. However, if the ERAD cannot handle the misfolded proteins, the cell activates the unfolded protein response or UPR to adjust the protein folding...
5.6K
01:17Role of ER in the Secretory Pathway
6.2K
Eukaryotic cells have a special pathway that enables communication between various intracellular membrane-bound compartments and also with the extracellular environment. This pathway is termed as the secretory pathway.
Components of the secretory pathway
About a third of proteins synthesized in the cell are sorted via the secretory route. They shuffle between different compartments in membrane-bound vesicles until they reach their final destination. The main intracellular compartments involved...
Components of the secretory pathway
About a third of proteins synthesized in the cell are sorted via the secretory route. They shuffle between different compartments in membrane-bound vesicles until they reach their final destination. The main intracellular compartments involved...
6.2K
01:22Role of Ephrin-Eph Signalling in Intestinal Stem Cell Renewal
2.4K
Erythropoietin-producing hepatocellular carcinoma receptor (Eph) and its ligand, Eph receptor-interacting protein (Ephrin) were first discovered in the human carcinoma cell line, hence the name. Ephrin-Eph interaction guides cells to reach their appropriate location in adult tissues. They also play an essential role in the immune system by helping in immune cell migration, adhesion, and activation. Based on their structure and function, Eph is divided into two classes — EphA and EphB.
2.4K
01:32Export of Misfolded Proteins out of the ER
4.5K
After folding, the ER assesses the quality of secretory and membrane proteins. The correctly folded proteins are cleared by the calnexin cycle for transport to their final destination, while misfolded proteins are held back in the ER lumen. The ER chaperones attempt to unfold and refold the misfolded proteins but sometimes fail to achieve the correct native conformation. Such terminally misfolded proteins are then exported to the cytosol by ER-associated degradation or ERAD pathway for...
4.5K
01:26Protein Modifications in the RER
6.1K
Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal...
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal...
6.1K