Biological Activity
4μ8C (IRE1 Inhibitor III) is a small-molecule inhibitor of IRE1α.
In Vitro
When applies to the media of ER stressed cultured cells, 4μ8C inhibits Xbp1 splicing in a concentration-dependent manner. 4μ8C dissociates slowly from IRE1, but ishout of inhibitor leads to rapid recovery of Xbp1 splicing in cells[1].The IRE1 endoribonuclease inhibitor 4μ8c prevents the splicing of the XBP1 mRNA in response to ER stress caused by mutant proinsulin production[2]. The inositol-requiring enzyme 1α (IRE1α) is a serine-threonine kinase that plays crucial roles in activating the unfolded protein response. 4μ8C treatment dramatically inhibits IL-4 production by CD4+ T cells under Th0 conditions because both the IL-4 levels in the culture supernatant and the percentage of IL-4 positive cells are reduced by 4μ8C treatment. In addition, both IL-5 and IL-13 production are significantly reduced upon treatment with 4μ8C[3].
In Vivo
4μ8C reverses the ER stress-dependent loss of several known RIDD targets, with an EC50 of approximately 4 μM, approximating that of inhibition of XBP1 target gene activation[1].
References & source
Published experimental findings depend on the model and assay conditions. They do not guarantee equivalent performance in every application. For laboratory research use only.