6w3b

Publication Abstract from PubMed

Inositol-Requiring Enzyme 1 (IRE1) is an essential component of the Unfolded Protein Response. IRE1 spans the endoplasmic reticulum membrane, comprising a sensory lumenal domain, and tandem kinase and endoribonuclease (RNase) cytoplasmic domains. Excess unfolded proteins in the ER lumen induce dimerization and oligomerization of IRE1, triggering kinase trans-autophosphorylation and RNase activation. Known ATP-competitive small-molecule IRE1 kinase inhibitors either allosterically disrupt or stabilize the active dimeric unit, accordingly inhibiting or stimulating RNase activity. Previous allosteric RNase activators display poor selectivity and/or weak cellular activity. In this study, we describe a class of ATP-competitive RNase activators possessing high selectivity and strong cellular activity. This class of activators binds IRE1 in the kinase front pocket, leading to a distinct conformation of the activation loop. Our findings reveal exquisitely precise interdomain regulation within IRE1, advancing the mechanistic understanding of this important enzyme and its investigation as a potential small-molecule therapeutic target.

Activation of the IRE1 RNase through remodeling of the kinase front pocket by ATP-competitive ligands.,Ferri E, Le Thomas A, Wallweber HA, Day ES, Walters BT, Kaufman SE, Braun MG, Clark KR, Beresini MH, Mortara K, Chen YA, Canter B, Phung W, Liu PS, Lammens A, Ashkenazi A, Rudolph J, Wang W Nat Commun. 2020 Dec 14;11(1):6387. doi: 10.1038/s41467-020-19974-5. PMID:33318494^[4]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.