title: Identification of Orai1 channel inhibitors by using minimal functional domains to screen small molecule microarrays.
abstract: Store-operated calcium (SOC) channels are vital for activation of the immune cells, and mutations in the channel result in severe combined immunodeficiency in human patients. In lymphocytes, SOC entry is mediated by the Orai1 channel, which is activated by direct binding of STIM1. Here we describe an alternative approach for identifying inhibitors of SOC entry using minimal functional domains of STIM1 and Orai1 to screen a small-molecule microarray. This screen identified AnCoA4, which inhibits SOC entry at submicromolar concentrations and blocks T cell activation in vitro and in vivo. Biophysical studies revealed that AnCoA4 binds to the C terminus of Orai1, directly inhibiting calcium influx through the channel and also reducing binding of STIM1. AnCoA4, unlike other reported SOC inhibitors, is a molecule with a known binding site and mechanism of action. These studies also provide proof of principle for an approach to ion channel drug discovery.
authors.affiliation: Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Novartis Institutes for Biomedical Research, Cambridge, MA 02139, USA.
authors.forename: Amir Masoud
authors.initials: AM
authors.lastname: Sadaghiani
authors.affiliation: Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), 689-798 Ulsan, South Korea.
authors.forename: Sang Min
authors.initials: SM
authors.lastname: Lee
authors.affiliation: Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Justin I
authors.initials: JI
authors.lastname: Odegaard
authors.affiliation: Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Dennis B
authors.initials: DB
authors.lastname: Leveson-Gower
authors.affiliation: Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA.
authors.forename: Olivia M
authors.initials: OM
authors.lastname: McPherson
authors.affiliation: Department of Chemistry, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Novick
authors.affiliation: Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), 689-798 Ulsan, South Korea.
authors.forename: Mi Ri
authors.initials: MR
authors.lastname: Kim
authors.affiliation: Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA.
authors.forename: Angela N
authors.initials: AN
authors.lastname: Koehler
authors.affiliation: Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Negrin
authors.affiliation: Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Novartis Institutes for Biomedical Research, Cambridge, MA 02139, USA. Electronic address: ricardo.dolmetsch@novartis.com.
authors.forename: Ricardo E
authors.initials: RE
authors.lastname: Dolmetsch
authors.affiliation: Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), 689-798 Ulsan, South Korea. Electronic address: cypark@unist.ac.kr.
authors.forename: Chan Young
authors.initials: CY
authors.lastname: Park
mesh_terms: D000818:Animals; D052117:Benzodioxoles / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D002867:Chromones / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D004195:Disease Models, Animal; D004330:Drosophila; D029721:Drosophila Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D016257:Fura-2 / Q000737:chemistry; D015870:Gene Expression / Q000187:drug effects; D057809:HEK293 Cells; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D007166:Immunosuppressive Agents / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D008213:Lymphocyte Activation / Q000187:drug effects; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D062105:Molecular Docking Simulation; D009363:Neoplasm Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000071740:ORAI1 Protein; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D054852:Small Molecule Libraries / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D000071737:Stromal Interaction Molecule 1; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism
chemical_list: C000599361:AnCoA4 compound; D052117:Benzodioxoles; D002867:Chromones; D029721:Drosophila Proteins; D007166:Immunosuppressive Agents; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D000071740:ORAI1 Protein; D011994:Recombinant Proteins; C103530:STIM1 protein, human; D054852:Small Molecule Libraries; D000071737:Stromal Interaction Molecule 1; C510747:olf186-F protein, Drosophila; D016257:Fura-2