title: A Covalent Cysteine-Targeting Kinase Inhibitor of Ire1 Permits Allosteric Control of Endoribonuclease Activity.
abstract: The unfolded protein response (UPR) initiated by the transmembrane kinase/ribonuclease Ire1 has been implicated in a variety of diseases. Ire1, with its unique position in the UPR, is an ideal target for the development of therapies; however, the identification of specific kinase inhibitors is challenging. Recently, the development of covalent inhibitors has gained great momentum because of the irreversible deactivation of the target. We identified and determined the mechanism of action of the Ire1-inhibitory compound UPRM8. MS analysis revealed that UPRM8 inhibition occurs by covalent adduct formation at a conserved cysteine at the regulatory DFG+2 position in the Ire1 kinase activation loop. Mutational analysis of the target cysteine residue identified both UPRM8-resistant and catalytically inactive Ire1 mutants. We describe a novel covalent inhibition mechanism of UPRM8, which can serve as a lead for the rational design and optimization of inhibitors of human Ire1.
authors.affiliation: Department of Medicine, McGill University, 1001 Boulevard Décarie, Montréal, QC, H4A 3J1, Canada. daniel.waller@mail.mcgill.ca.|Department of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montréal, QC, H3G 1Y6, Canada. daniel.waller@mail.mcgill.ca.
authors.forename: Daniel D
authors.identifier: 0000-0002-8291-2630
authors.initials: DD
authors.lastname: Waller
authors.affiliation: Department of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montréal, QC, H3G 1Y6, Canada.
authors.forename: Gregor
authors.initials: G
authors.lastname: Jansen
authors.affiliation: Pharmaqam, Département de Chimie, Université du Québec à Montréal, Montréal, QC, H3C 3P8, Canada.
authors.forename: Makan
authors.initials: M
authors.lastname: Golizeh
authors.affiliation: Department of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montréal, QC, H3G 1Y6, Canada.
authors.forename: Chloe
authors.initials: C
authors.lastname: Martel-Lorion
authors.affiliation: Department of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montréal, QC, H3G 1Y6, Canada.
authors.forename: Kurt
authors.initials: K
authors.lastname: Dejgaard
authors.affiliation: Pharmaqam, Département de Chimie, Université du Québec à Montréal, Montréal, QC, H3C 3P8, Canada.
authors.forename: Tze Chieh
authors.initials: TC
authors.lastname: Shiao
authors.affiliation: Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montréal, QC, H3G 1Y6, Canada.
authors.forename: John
authors.initials: J
authors.lastname: Mancuso
authors.affiliation: Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montréal, QC, H3G 1Y6, Canada.
authors.forename: Youla S
authors.initials: YS
authors.lastname: Tsantrizos
authors.affiliation: Pharmaqam, Département de Chimie, Université du Québec à Montréal, Montréal, QC, H3C 3P8, Canada.
authors.forename: René
authors.initials: R
authors.lastname: Roy
authors.affiliation: Department of Medicine, McGill University, 1001 Boulevard Décarie, Montréal, QC, H4A 3J1, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Sebag
authors.affiliation: Pharmaqam, Département de Chimie, Université du Québec à Montréal, Montréal, QC, H3C 3P8, Canada.
authors.forename: Lekha
authors.initials: L
authors.lastname: Sleno
authors.affiliation: Department of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montréal, QC, H3G 1Y6, Canada.
authors.forename: David Y
authors.initials: DY
authors.lastname: Thomas
mesh_terms: D000494:Allosteric Regulation; D000595:Amino Acid Sequence; D055162:Biocatalysis; D003545:Cysteine / Q000378:metabolism*; D004722:Endoribonucleases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D047428:Protein Kinase Inhibitors / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D011744:Pyrimidinones / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D056811:Unfolded Protein Response / Q000187:drug effects
chemical_list: D047428:Protein Kinase Inhibitors; D011744:Pyrimidinones; D029701:Saccharomyces cerevisiae Proteins; C000616453:UPRM8 compound; C528229:ERN1 protein, human; D017346:Protein Serine-Threonine Kinases; D004722:Endoribonucleases; D003545:Cysteine
keywords: Ire1; Xbp1; endoplasmic reticulum stress; enzyme catalysis; inhibitors; type IV kinase inhibitor