title: Discovery of small molecule inhibitors of the PH domain leucine-rich repeat protein phosphatase (PHLPP) by chemical and virtual screening.
abstract: PH domain Leucine-rich repeat protein phosphatase (PHLPP) directly dephosphorylates and inactivates Akt and protein kinase C, poising it as a prime target for pharmacological intervention of two major survival pathways. Here we report on the discovery of small molecule inhibitors of the phosphatase activity of PHLPP, a member of the PP2C family of phosphatases for which there are no general pharmacological inhibitors. First, the Diversity Set of the NCI was screened for inhibition of the purified phosphatase domain of PHLPP2 in vitro. Second, selected libraries from the open NCI database were docked into a virtual model of the phosphatase domain of PHLPP2, previously trained with our experimental data set, unveiling additional inhibitors. Biochemical and cellular assays resulted in the identification of two structurally diverse compounds that selectively inhibit PHLPP in vitro, increase Akt signaling in cells, and prevent apoptosis. Thus, chemical and virtual screening has resulted in the identification of small molecules that promote Akt signaling by inhibiting its negative regulator PHLPP.
authors.affiliation: Department of Pharmacology, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093.
authors.forename: Emma
authors.initials: E
authors.lastname: Sierecki
authors.forename: William
authors.initials: W
authors.lastname: Sinko
authors.forename: J Andrew
authors.initials: JA
authors.lastname: McCammon
authors.forename: Alexandra C
authors.initials: AC
authors.lastname: Newton
mesh_terms: D000595:Amino Acid Sequence; D000880:Anthraquinones / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001391:Azo Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D020134:Catalytic Domain; D045744:Cell Line, Tumor; D029968:Escherichia coli Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry; D057166:High-Throughput Screening Assays; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors* / Q000737:chemistry; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000819:agonists / Q000378:metabolism; D012459:Salicylates / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid; D054852:Small Molecule Libraries
chemical_list: C553279:1,3-((4-(2,4-diamino-5-methylphenyl)diazenylphenyl)hydrazinylidene)-6-oxocyclohexa-1,4-diene-1-carboxylic acid; C553278:1-amino-9,10-dioxo-4-(3-sulfamoylanilino)anthracene-2-sulfonic acid; D000880:Anthraquinones; D001391:Azo Compounds; D029968:Escherichia coli Proteins; D012459:Salicylates; D054852:Small Molecule Libraries; D051057:Proto-Oncogene Proteins c-akt; D010749:Phosphoprotein Phosphatases