CENP-E--dependent BubR1 autophosphorylation enhances chromosome alignment and the mitotic checkpoint.
How the state of spindle microtubule capture at the kinetochore is translated into mitotic checkpoint signaling remains largely unknown. In this paper, we demonstrate that the kinetochore-associated mitotic kinase BubR1 phosphorylates itself in human cells and that this autophosphorylation is dependent on its binding partner, the kinetochore motor CENP-E. This CENP-E-dependent BubR1 autophosphorylation at unattached kinetochores is important for a full-strength mitotic checkpoint to prevent single chromosome loss. Replacing endogenous BubR1 with a nonphosphorylatable BubR1 mutant, as well as depletion of CENP-E, the BubR1 kinase activator, results in metaphase chromosome misalignment and a decrease of Aurora B-mediated Ndc80 phosphorylation at kinetochores. Furthermore, expressing a phosphomimetic BubR1 mutant substantially reduces the incidence of polar chromosomes in CENP-E-depleted cells. Thus, the state of CENP-E-dependent BubR1 autophosphorylation in response to spindle microtubule capture by CENP-E is important for kinetochore function in achieving accurate chromosome segregation.
Department of Pathology and Cell Biology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
Yige
Y
Guo
Christine
C
Kim
Sana
S
Ahmad
Jiayin
J
Zhang
Yinghui
Y
Mao
D064107:Aurora Kinase B; D064127:Aurora Kinases; D002460:Cell Line; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D002875:Chromosomes / Q000378:metabolism*; D003598:Cytoskeletal Proteins; D006801:Humans; D018386:Kinetochores / Q000378:metabolism; D059566:M Phase Cell Cycle Checkpoints / Q000502:physiology*; D008677:Metaphase / Q000502:physiology; D009154:Mutation; D009687:Nuclear Proteins / Q000378:metabolism; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*
D002868:Chromosomal Proteins, Non-Histone; D003598:Cytoskeletal Proteins; C120529:NDC80 protein, human; D009687:Nuclear Proteins; C068688:centromere protein E; C576921:AURKB protein, human; D064107:Aurora Kinase B; D064127:Aurora Kinases; C584277:BUB1 protein, human; C090464:Bub1 spindle checkpoint protein; D017346:Protein Serine-Threonine Kinases