Proinsulin misfolding, an established cause of diabetes in patients with INS gene mutations, is now observed in normal human pancreatic islets, and rodents with genetic predisposition to type 2 diabetes.
Mutations causing proinsulin misfolding trigger unfolded protein response and lead to impaired proliferation and reduced mTORC1 signalling of developing beta-cells in a patient-derived induced pluripotent stem cell disease model.
ATP enters the endoplasmic reticulum (ER) lumen through an SLC35B1/AXER-dependentCaATiER mechanism, and ATP usage in the ER renders 'anti-Warburg' effect by increasing ATP regeneration from OxPhos while decreasing glycolysis.
Integrated stress response-induced expression of ATF4 and its transactivation of SOX9 causes aberrant chondrocyte differentiation and skeletal defects which can be alleviated by modulating initiation-factor eIF2α phosphorylation translation control.
ER-stress sensing mechanism of the unfolded protein response sensor/transducer IRE1 is conserved from yeast to mammals, where in mammals, unfolded protein binding to IRE1's ER lumenal domain is coupled to its oligomerization and activation through an allosteric conformational change.