A cell-permeable coumarin o-hydroxyaldehyde that inhibits IRE1 RNase activity in a time- and dose-dependent manner (IC50=550 and 45nM, respectively, with 0 and 16min drug preincubation in RNA cleavage assays) by covalently targeting IRE1 Lys907 via Schiff base formation, effectively preventing ER stress-induced site-specific mRNA splicing as well as RIDD (Regulated IRE1-Dependent Degradation) mRNA degradation (IC50=6.9 and 4.1uM, respectively, against Xbp1 splicing and Scara3 degradation) in MEF cultures following Tunicamycin treatment. Comparing to STF083010, 4u8C is also shown to inhibit IRE1 autophosphorylation in cell-free assays via Schiff base formation with IRE1 Lys599 in the absence of ADP, however cellular nucleotide prevents 4u8C from targeting IRE1 Lys599 intracellularly.
Formula:C11H8O4
Molecular Weight:204.2
Solubility:DMSO (25mg/ml)
Storage and Stability:Lyophilized powder may be stored at -20°C. Stable for 12 months at -20°C. Reconstitute with sterile ddH2O. Aliquot to avoid repeated freezing and thawing. Store at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
