VIB Center for Medical Biotechnology, Ghent, Belgium.
Department of Biomolecular Medicine, Ghent University, Ghent, Belgium.
Mucosal Immunol. 2021 Nov;14(6):1235-1246. doi: 10.1038/s41385-021-00412-8. Epub 2021 Jun 1.
Barrier epithelial cells lining the mucosal surfaces of the gastrointestinal and respiratory tracts interface directly with the environment. As such, these tissues are continuously challenged to maintain a healthy equilibrium between immunity and tolerance against environmental toxins, food components, and microbes. An extracellular mucus barrier, produced and secreted by the underlying epithelium plays a central role in this host defense response. Several dedicated molecules with a unique tissue-specific expression in mucosal epithelia govern mucosal homeostasis. Here, we review the biology of Inositol-requiring enzyme 1β (IRE1β), an ER-resident endonuclease and paralogue of the most evolutionarily conserved ER stress sensor IRE1α. IRE1β arose through gene duplication in early vertebrates and adopted functions unique from IRE1α which appear to underlie the basic development and physiology of mucosal tissues.
衬于胃肠道和呼吸道黏膜表面的屏障上皮细胞直接与环境接触。因此，这些组织不断面临着在免疫和耐受环境毒素、食物成分和微生物之间保持健康平衡的挑战。由下层上皮细胞产生和分泌的细胞外黏液屏障在这种宿主防御反应中起着核心作用。几种在黏膜上皮细胞中具有独特组织特异性表达的专用分子调节黏膜稳态。在这里，我们回顾了肌醇需求酶 1β（IRE1β）的生物学特性，IRE1β 是内质网驻留内切酶和最进化保守的内质网应激传感器 IRE1α 的同源物。IRE1β 是通过早期脊椎动物的基因复制产生的，其功能与 IRE1α 不同，这似乎是黏膜组织基本发育和生理学的基础。
