6w3k

Structure of unphosphorylated human IRE1 bound to G-9807Structure of unphosphorylated human IRE1 bound to G-9807

Structural highlights

6w3k is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.08Å
Ligands:
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

ERN1_HUMAN Senses unfolded proteins in the lumen of the endoplasmic reticulum via its N-terminal domain which leads to enzyme auto-activation. The active endoribonuclease domain splices XBP1 mRNA to generate a new C-terminus, converting it into a potent unfolded-protein response transcriptional activator and triggering growth arrest and apoptosis.^[1] ^[2] ^[3] [UniProtKB:Q9EQY0]

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.

References

↑ Tirasophon W, Welihinda AA, Kaufman RJ. A stress response pathway from the endoplasmic reticulum to the nucleus requires a novel bifunctional protein kinase/endoribonuclease (Ire1p) in mammalian cells. Genes Dev. 1998 Jun 15;12(12):1812-24. PMID:9637683
↑ Iwawaki T, Hosoda A, Okuda T, Kamigori Y, Nomura-Furuwatari C, Kimata Y, Tsuru A, Kohno K. Translational control by the ER transmembrane kinase/ribonuclease IRE1 under ER stress. Nat Cell Biol. 2001 Feb;3(2):158-64. PMID:11175748 doi:10.1038/35055065
↑ Liu CY, Xu Z, Kaufman RJ. Structure and intermolecular interactions of the luminal dimerization domain of human IRE1alpha. J Biol Chem. 2003 May 16;278(20):17680-7. Epub 2003 Mar 13. PMID:12637535 doi:10.1074/jbc.M300418200
↑ 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. Activation of the IRE1 RNase through remodeling of the kinase front pocket by ATP-competitive ligands. Nat Commun. 2020 Dec 14;11(1):6387. doi: 10.1038/s41467-020-19974-5. PMID:33318494 doi:http://dx.doi.org/10.1038/s41467-020-19974-5

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OCA

[1] Tirasophon W, Welihinda AA, Kaufman RJ. A stress response pathway from the endoplasmic reticulum to the nucleus requires a novel bifunctional protein kinase/endoribonuclease (Ire1p) in mammalian cells. Genes Dev. 1998 Jun 15;12(12):1812-24. PMID:9637683

[2] Iwawaki T, Hosoda A, Okuda T, Kamigori Y, Nomura-Furuwatari C, Kimata Y, Tsuru A, Kohno K. Translational control by the ER transmembrane kinase/ribonuclease IRE1 under ER stress. Nat Cell Biol. 2001 Feb;3(2):158-64. PMID:11175748 doi:10.1038/35055065

[3] Liu CY, Xu Z, Kaufman RJ. Structure and intermolecular interactions of the luminal dimerization domain of human IRE1alpha. J Biol Chem. 2003 May 16;278(20):17680-7. Epub 2003 Mar 13. PMID:12637535 doi:10.1074/jbc.M300418200

[4] 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. Activation of the IRE1 RNase through remodeling of the kinase front pocket by ATP-competitive ligands. Nat Commun. 2020 Dec 14;11(1):6387. doi: 10.1038/s41467-020-19974-5. PMID:33318494 doi:http://dx.doi.org/10.1038/s41467-020-19974-5

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