title: Structure and mechanism of action of the hydroxy-aryl-aldehyde class of IRE1 endoribonuclease inhibitors.
abstract: Endoplasmic reticulum (ER) stress activates the unfolded protein response and its dysfunction is linked to multiple diseases. The stress transducer IRE1α is a transmembrane kinase endoribonuclease (RNase) that cleaves mRNA substrates to re-establish ER homeostasis. Aromatic ring systems containing hydroxy-aldehyde moieties, termed hydroxy-aryl-aldehydes (HAA), selectively inhibit IRE1α RNase and thus represent a novel chemical series for therapeutic development. We solved crystal structures of murine IRE1α in complex with three HAA inhibitors. HAA inhibitors engage a shallow pocket at the RNase-active site through pi-stacking interactions with His910 and Phe889, an essential Schiff base with Lys907 and a hydrogen bond with Tyr892. Structure-activity studies and mutational analysis of contact residues define the optimal chemical space of inhibitors and validate the inhibitor-binding site. These studies lay the foundation for understanding both the biochemical and cellular functions of IRE1α using small molecule inhibitors and suggest new avenues for inhibitor design.
authors.affiliation: 1] Centre for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5 [2].
authors.forename: Mario
authors.initials: M
authors.lastname: Sanches
authors.affiliation: 1] Centre for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5 [2].
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Duffy
authors.affiliation: 1] Centre for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5 [2] Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8 [3].
authors.forename: Manisha
authors.initials: M
authors.lastname: Talukdar
authors.affiliation: 1] Centre for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5 [2] Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada M5S 1A8.
authors.forename: Nero
authors.initials: N
authors.lastname: Thevakumaran
authors.affiliation: Centre for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5.
authors.forename: David
authors.initials: D
authors.lastname: Chiovitti
authors.affiliation: Centre for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5.
authors.forename: Marella D
authors.initials: MD
authors.lastname: Canny
authors.affiliation: 1] Centre for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5 [2] Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Lee
authors.affiliation: NE-CAT APS, Building 436E, Argonne National Lab, 9700 S.Cass Avenue, Argonne, Illinois 60439, USA.
authors.forename: Igor
authors.initials: I
authors.lastname: Kurinov
authors.affiliation: Drug Discovery Program, Ontario Institute for Cancer Research, Toronto, Ontario, Canada M5G 0A3.
authors.forename: David
authors.initials: D
authors.lastname: Uehling
authors.affiliation: 1] Drug Discovery Program, Ontario Institute for Cancer Research, Toronto, Ontario, Canada M5G 0A3 [2] Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada M5S 1A8.
authors.forename: Rima
authors.initials: R
authors.lastname: Al-awar
authors.affiliation: Drug Discovery Program, Ontario Institute for Cancer Research, Toronto, Ontario, Canada M5G 0A3.
authors.forename: Gennadiy
authors.initials: G
authors.lastname: Poda
authors.affiliation: Drug Discovery Program, Ontario Institute for Cancer Research, Toronto, Ontario, Canada M5G 0A3.
authors.forename: Michael
authors.initials: M
authors.lastname: Prakesch
authors.affiliation: Drug Discovery Program, Ontario Institute for Cancer Research, Toronto, Ontario, Canada M5G 0A3.
authors.forename: Brian
authors.initials: B
authors.lastname: Wilson
authors.affiliation: MannKind Corporation, 28903 North Avenue Paine, Valencia, California 91355, USA.
authors.forename: Victor
authors.initials: V
authors.lastname: Tam
authors.affiliation: MannKind Corporation, 28903 North Avenue Paine, Valencia, California 91355, USA.
authors.forename: Colleen
authors.initials: C
authors.lastname: Schweitzer
authors.affiliation: MannKind Corporation, 28903 North Avenue Paine, Valencia, California 91355, USA.
authors.forename: Andras
authors.initials: A
authors.lastname: Toro
authors.affiliation: MannKind Corporation, 28903 North Avenue Paine, Valencia, California 91355, USA.
authors.forename: Julie L
authors.initials: JL
authors.lastname: Lucas
authors.affiliation: MannKind Corporation, 28903 North Avenue Paine, Valencia, California 91355, USA.
authors.forename: Danka
authors.initials: D
authors.lastname: Vuga
authors.affiliation: NanoTemper Technologies, Inc., 395 Oyster Point Boulevard, Suite 135, South San Francisco, California 94080, USA.
authors.forename: Lynn
authors.initials: L
authors.lastname: Lehmann
authors.affiliation: 1] Centre for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5 [2] Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8.
authors.forename: Daniel
authors.initials: D
authors.lastname: Durocher
authors.affiliation: MannKind Corporation, 28903 North Avenue Paine, Valencia, California 91355, USA.
authors.forename: Qingping
authors.initials: Q
authors.lastname: Zeng
authors.affiliation: MannKind Corporation, 28903 North Avenue Paine, Valencia, California 91355, USA.
authors.forename: John B
authors.initials: JB
authors.lastname: Patterson
authors.affiliation: 1] Centre for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5 [2] Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8 [3] Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada M5S 1A8.
authors.forename: Frank
authors.initials: F
authors.lastname: Sicheri
mesh_terms: D000447:Aldehydes / Q000737:chemistry / Q000494:pharmacology; D001547:Benzaldehydes / Q000737:chemistry / Q000494:pharmacology; D001665:Binding Sites; D018957:CD59 Antigens / Q000378:metabolism; D020134:Catalytic Domain; D045744:Cell Line, Tumor / Q000187:drug effects; D003374:Coumarins / Q000737:chemistry / Q000494:pharmacology; D018360:Crystallography, X-Ray; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000235:genetics; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D008565:Membrane Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015394:Molecular Structure; D009025:Morpholines / Q000737:chemistry / Q000494:pharmacology; D010954:Plasmacytoma / Q000188:drug therapy / Q000473:pathology; D011487:Protein Conformation; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000071701:Regulatory Factor X Transcription Factors; D012260:Ribonucleases / Q000378:metabolism; D054852:Small Molecule Libraries / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000235:genetics
chemical_list: D000447:Aldehydes; D001547:Benzaldehydes; D018957:CD59 Antigens; D003374:Coumarins; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; C000604516:MKC9989; D008565:Membrane Proteins; D009025:Morpholines; C000604515:OICR464; C000604517:OICR573; D000071701:Regulatory Factor X Transcription Factors; D054852:Small Molecule Libraries; D014157:Transcription Factors; C051590:CD59 protein, human; C486556:Ern2 protein, mouse; D017346:Protein Serine-Threonine Kinases; D012260:Ribonucleases