Protein folding homeostasis in the lumen of the endoplasmic reticulum is defended by signal transduction pathways that are activated by an imbalance between unfolded proteins and chaperones (so called ER stress). Collectively referred to as the unfolded protein response (UPR) this homeostatic response is initiated by three known ER stress transducers: IRE1, PERK and ATF6. These ER-localised transmembrane (TM) proteins posses lumenal stress sensing domains and cytosolic effector domains that collectively activate a gene expression programme regulating the production of proteins involved in the processing and maturation of secreted proteins that enter the ER. However, beyond limiting unfolded protein stress in the ER the UPR has important connections to lipid metabolism that are the subject of this review.

中文翻译：

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脂质对未折叠蛋白反应的调节。

内质网内腔中的蛋白质折叠稳态通过信号转导途径来防御，该信号转导途径由未折叠的蛋白质和分子伴侣之间的不平衡激活（所谓的ER应激）。该稳态反应统称为未折叠蛋白应答（UPR），它是由三种已知的ER应激传感器：IRE1，PERK和ATF6引发的。这些ER定位的跨膜（TM）蛋白具有管腔应力感测域和胞质效应域，它们共同激活基因表达程序，该程序调控参与进入ER的分泌蛋白的加工和成熟的蛋白的生产。然而，除了限制急诊室中展开的蛋白质应激外，UPR与脂质代谢有着重要的联系，这是本综述的主题。