ATF6 Inhibitor

IBT21 is an endoplasmic reticulum stress inhibitor that binds to unfolded or misfolded proteins and prevents their aggregation. IBT21 inhibits UPR activation of the ATF6, IRE1 and PERK branches under ER stress, with IC₅₀ values of 0.24 μM, 0.33 μM, and 0.46 μM, respectively. IBT21 protects cells from ER stress-induced death and mutant prion protein (protein toxin)-induced growth inhibition. IBT21 exhibits chemical chaperone activity distinct from UPR modulators, does not affect protein translation, moderately reduces DTT (HY-15917)-induced ER stress, and fails to inhibit the heat shock response. IBT21 is useful for research related to prion diseases.

LPPM-8 is a ligand of Med25 and an inhibitor of Med25 protein-protein interactions (PPIs). LPPM-8 engages Med25 through interaction with the H2 face of its Activator Interaction Domain and stabilizes full-length protein in the cellular proteome. LPPM-8 is an orthosteric inhibitor of H2-binding transcriptional activators (such as ATF6a). LPPM-8 can be used for studying Med25 and Mediator complex biology.

Rosolic acid is a Michael acceptor molecule isolated from the rhizomes of Plantago asiatica L. Rosolic acid inhibits Keap1, promotes Nrf2 nuclear translocation, and upregulates HO-1 and NQO-1. Rosolic acid reduces ER stress markers PERK, ATF-6, GRP78, and CHOP, as well as oxidative stress, ROS production, inflammation, and apoptosis. Rosolic acid upregulates SOD, CAT, and GPx activities, induces angiogenesis and insulin secretion, and restores endothelial function and pancreatic beta cell protection under ER stress. Rosolic acid can be used in research on diabetes and endothelial dysfunction.