title: Microtubule capture by CENP-E silences BubR1-dependent mitotic checkpoint signaling.
abstract: The mitotic checkpoint is the major cell cycle control mechanism for maintaining chromosome content in multicellular organisms. Prevention of premature onset of anaphase requires activation at unattached kinetochores of the BubR1 kinase, which acts with other components to generate a diffusible "stop anaphase" inhibitor. Not only does direct binding of BubR1 to the centromere-associated kinesin family member CENP-E activate its essential kinase, binding of a motorless fragment of CENP-E is shown here to constitutively activate BubR1 bound at kinetochores, producing checkpoint signaling that is not silenced either by spindle microtubule capture or the tension developed at those kinetochores by other components. Using purified BubR1, microtubules, and CENP-E, microtubule capture by the CENP-E motor domain is shown to silence BubR1 kinase activity in a ternary complex of BubR1-CENP-E-microtubule. Together, this reveals that CENP-E is the signal transducing linker responsible for silencing BubR1-dependent mitotic checkpoint signaling through its capture at kinetochores of spindle microtubules.
authors.affiliation: Ludwig Institute for Cancer Research, University of California at San Diego, La Jolla, CA 92093, USA.
authors.forename: Yinghui
authors.initials: Y
authors.lastname: Mao
authors.forename: Arshad
authors.initials: A
authors.lastname: Desai
authors.forename: Don W
authors.initials: DW
authors.lastname: Cleveland
mesh_terms: D000818:Animals; D002417:Cattle; D018797:Cell Cycle Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002457:Cell Extracts; D045744:Cell Line, Tumor; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004789:Enzyme Activation; D005260:Female; D005455:Fluorescent Antibody Technique; D005456:Fluorescent Dyes; D020868:Gene Silencing; D005982:Glutathione Transferase / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D018386:Kinetochores / Q000378:metabolism; D008870:Microtubules / Q000235:genetics / Q000378:metabolism*; D008938:Mitosis; D008954:Models, Biological; D009865:Oocytes / Q000737:chemistry; D017354:Point Mutation; D011494:Protein Kinases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D017434:Protein Structure, Tertiary / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D012235:Rhodamines; D015398:Signal Transduction; D014404:Tubulin / Q000378:metabolism; D014981:Xenopus
chemical_list: D018797:Cell Cycle Proteins; D002457:Cell Extracts; D002868:Chromosomal Proteins, Non-Histone; D005456:Fluorescent Dyes; D011994:Recombinant Proteins; D012235:Rhodamines; D014404:Tubulin; C068688:centromere protein E; C004805:5'-guanylylmethylenebisphosphonate; D006160:Guanosine Triphosphate; D005982:Glutathione Transferase; D011494:Protein Kinases; C584277:BUB1 protein, human; C090464:Bub1 spindle checkpoint protein; D017346:Protein Serine-Threonine Kinases