title: Towards the Development of Small-Molecule MO25 Binders as Potential Indirect SPAK/OSR1 Kinase Inhibitors.
abstract: The binding of the scaffolding protein MO25 to SPAK and OSR1 protein kinases, which regulate ion homeostasis, causes increases of up to 100-fold in their catalytic activity. Various animal models have shown that the inhibition of SPAK and OSR1 lowers blood pressure, and so here we present a new indirect approach to inhibiting SPAK and OSR1 kinases by targeting their protein partner MO25. To explore this approach, we developed a fluorescent polarisation assay and used it in screening of a small in-house library of ≈4000 compounds. This led to the identification of one compound-HK01-as the first small-molecule inhibitor of the MO25-dependent activation of SPAK and OSR1 in vitro. Our data confirm the feasibility of targeting this protein-protein interaction by small-molecule compounds and highlights their potential to modulate ion co-transporters and thus cellular electrolyte balance.
authors.affiliation: School of Pharmacy, University of Birmingham, Edgbaston Park Road, Birmingham, B15 2TT, UK.
authors.forename: Hachemi
authors.initials: H
authors.lastname: Kadri
authors.affiliation: School of Pharmacy, University of Birmingham, Edgbaston Park Road, Birmingham, B15 2TT, UK.
authors.forename: Mubarak A
authors.initials: MA
authors.lastname: Alamri
authors.affiliation: Division of Biological Chemistry and Drug Discovery, University of Dundee, Dow Street, Dundee, DD1 5EH, UK.
authors.forename: Iva H
authors.initials: IH
authors.lastname: Navratilova
authors.affiliation: Birmingham Drug Discovery Facility, School of Biosciences, University of Birmingham, Edgbaston Park Road, Birmingham, B15 2TT, UK.
authors.forename: Luke J
authors.initials: LJ
authors.lastname: Alderwick
authors.affiliation: School of Chemistry, University of Birmingham, Edgbaston Park Road, Birmingham, B15 2TT, UK.
authors.forename: Nigel S
authors.initials: NS
authors.lastname: Simpkins
authors.affiliation: School of Pharmacy, University of Birmingham, Edgbaston Park Road, Birmingham, B15 2TT, UK.|School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff, CF10 3NB, UK.
authors.forename: Youcef
authors.identifier: 0000-0001-5720-8513
authors.initials: Y
authors.lastname: Mehellou
mesh_terms: D000818:Animals; D001665:Binding Sites; D001681:Biological Assay; D004789:Enzyme Activation / Q000187:drug effects; D057809:HEK293 Cells; D006801:Humans; D015151:Immunoblotting; D051379:Mice; D010649:Phenylalanine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D010797:Phthalimides / Q000737:chemistry* / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D054852:Small Molecule Libraries / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D014882:Water-Electrolyte Balance / Q000187:drug effects
chemical_list: C000621304:HK01 compound; D010797:Phthalimides; D047428:Protein Kinase Inhibitors; D054852:Small Molecule Libraries; D010649:Phenylalanine; C118135:OXSR1 protein, human; D017346:Protein Serine-Threonine Kinases; C486409:STK39 protein, human
keywords: MO25; OSR1; SPAK; high-throughput screening; inhibitors; scaffolding