title: An ent-kaurene that inhibits mitotic chromosome movement and binds the kinetochore protein ran-binding protein 2.
abstract: Using a chemical genetics screen, we have identified ent-15-oxokaurenoic acid (EKA) as a chemical that causes prolonged mitotic arrest at a stage resembling prometaphase. EKA inhibits the association of the mitotic motor protein centromeric protein E with kinetochores and inhibits chromosome movement. Unlike most antimitotic agents, EKA does not inhibit the polymerization or depolymerization of tubulin. To identify EKA-interacting proteins, we used a cell-permeable biotinylated form that retains biological activity to isolate binding proteins from living cells. Mass spectrometric analysis identified six EKA-binding proteins, including Ran-binding protein 2, a kinetochore protein whose depletion by small interfering RNA causes a similar mitotic arrest phenotype.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada.
authors.forename: Natalie T
authors.initials: NT
authors.lastname: Rundle
authors.forename: Jim
authors.initials: J
authors.lastname: Nelson
authors.forename: Mark R
authors.initials: MR
authors.lastname: Flory
authors.forename: Jomon
authors.initials: J
authors.lastname: Joseph
authors.forename: John
authors.initials: J
authors.lastname: Th'ng
authors.forename: Ruedi
authors.initials: R
authors.lastname: Aebersold
authors.forename: Mary
authors.initials: M
authors.lastname: Dasso
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Andersen
authors.forename: Michel
authors.initials: M
authors.lastname: Roberge
mesh_terms: D019921:Biotinylation; D045744:Cell Line, Tumor; D002621:Chemistry / Q000379:methods; D002875:Chromosomes / Q000648:ultrastructure*; D045786:Diterpenes, Kaurane / Q000737:chemistry* / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D021621:Imaging, Three-Dimensional; D018386:Kinetochores / Q000378:metabolism*; D013058:Mass Spectrometry; D008938:Mitosis; D018832:Molecular Chaperones / Q000378:metabolism*; D028861:Nuclear Pore Complex Proteins / Q000378:metabolism*; D011108:Polymers / Q000737:chemistry; D011485:Protein Binding; D008941:Spindle Apparatus; D014404:Tubulin / Q000737:chemistry
chemical_list: C516048:5-oxokaurenoic acid; D045786:Diterpenes, Kaurane; D018832:Molecular Chaperones; D028861:Nuclear Pore Complex Proteins; D011108:Polymers; D014404:Tubulin; C094493:ran-binding protein 2