title: Distinct domains in Bub1 localize RZZ and BubR1 to kinetochores to regulate the checkpoint.
abstract: The spindle assembly checkpoint (SAC) ensures proper chromosome segregation by delaying anaphase onset in response to unattached kinetochores. Checkpoint signalling requires the kinetochore localization of the Mad1-Mad2 complex that in more complex eukaryotes depends on the Rod-Zwilch-ZW10 (RZZ) complex. The kinetochore protein Zwint has been proposed to be the kinetochore receptor for RZZ, but here we show that Bub1 and not Zwint is required for RZZ recruitment. We find that the middle region of Bub1 encompassing a domain essential for SAC signalling contributes to RZZ localization. In addition, we show that a distinct region in Bub1 mediates kinetochore localization of BubR1 through direct binding, but surprisingly removal of this region increases checkpoint strength. Our work thus uncovers how Bub1 coordinates checkpoint signalling by distinct domains for RZZ and BubR1 recruitment and suggests that Bub1 localizes antagonistic checkpoint activities.
authors.affiliation: The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
authors.forename: Gang
authors.initials: G
authors.lastname: Zhang
authors.affiliation: The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Lischetti
authors.affiliation: The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Hayward
authors.affiliation: The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
authors.forename: Jakob
authors.initials: J
authors.lastname: Nilsson
mesh_terms: D000818:Animals; D059447:Cell Cycle Checkpoints; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D005347:Fibroblasts; D005455:Fluorescent Antibody Technique; D006367:HeLa Cells; D006801:Humans; D018386:Kinetochores / Q000378:metabolism*; D059566:M Phase Cell Cycle Checkpoints / Q000235:genetics; D064246:Mad2 Proteins / Q000378:metabolism; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism*; D017434:Protein Structure, Tertiary
chemical_list: D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; C489309:KNTC1 protein, human; C501384:MAD1L1 protein, human; C577697:MAD2L1 protein, human; D064246:Mad2 Proteins; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; C488261:ZW10 protein, human; C000606356:Zwilch protein, human; C584277:BUB1 protein, human; C584281:Bub1 protein, mouse; D017346:Protein Serine-Threonine Kinases