Kinetochore motors drive congression of peripheral polar chromosomes by overcoming random arm-ejection forces.
Accurate chromosome segregation during cell division in metazoans relies on proper chromosome congression at the equator. Chromosome congression is achieved after bi-orientation to both spindle poles shortly after nuclear envelope breakdown, or by the coordinated action of motor proteins that slide misaligned chromosomes along pre-existing spindle microtubules. These proteins include the minus-end-directed kinetochore motor dynein, and the plus-end-directed motors CENP-E at kinetochores and chromokinesins on chromosome arms. However, how these opposite and spatially distinct activities are coordinated to drive chromosome congression remains unknown. Here we used RNAi, chemical inhibition, kinetochore tracking and laser microsurgery to uncover the functional hierarchy between kinetochore and arm-associated motors, exclusively required for congression of peripheral polar chromosomes in human cells. We show that dynein poleward force counteracts chromokinesins to prevent stabilization of immature/incorrect end-on kinetochore-microtubule attachments and random ejection of polar chromosomes. At the poles, CENP-E becomes dominant over dynein and chromokinesins to bias chromosome ejection towards the equator. Thus, dynein and CENP-E at kinetochores drive congression of peripheral polar chromosomes by preventing arm-ejection forces mediated by chromokinesins from working in the wrong direction.
Chromosome Instability and Dynamics Laboratory, Institute for Molecular and Cell Biology, University of Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal.
Marin
M
Barisic
Instituto de Engenharia Biomédica, University of Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal.
Paulo
P
Aguiar
Biocenter, Division of Molecular Pathophysiology, Innsbruck Medical University, Innrain 80, 6020 Innsbruck, Austria.
Stephan
S
Geley
1] Chromosome Instability and Dynamics Laboratory, Institute for Molecular and Cell Biology, University of Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal [2] Cell Division Unit, Department of Experimental Biology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal.
Helder
H
Maiato
D064096:Aurora Kinase A / Q000037:antagonists & inhibitors; D064107:Aurora Kinase B / Q000037:antagonists & inhibitors; D001549:Benzamides / Q000494:pharmacology; D001552:Benzazepines / Q000494:pharmacology; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D002455:Cell Division; D045744:Cell Line, Tumor; D002868:Chromosomal Proteins, Non-Histone / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D020090:Chromosome Segregation / Q000502:physiology*; D056445:Cytoplasmic Dyneins / Q000235:genetics; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics; D004398:Dyneins / Q000378:metabolism*; D006801:Humans; D016547:Kinesins / Q000096:biosynthesis / Q000235:genetics; D018386:Kinetochores / Q000378:metabolism*; D008870:Microtubules / Q000235:genetics / Q000378:metabolism; D011799:Quinazolines / Q000494:pharmacology; D034622:RNA Interference; D034741:RNA, Small Interfering; D012521:Sarcosine / Q000031:analogs & derivatives / Q000494:pharmacology; D008941:Spindle Apparatus / Q000502:physiology*
C474722:4-(4-(N-benzoylamino)anilino)-6-methoxy-7-(3-(1-morpholino)propoxy)quinazoline; D001549:Benzamides; D001552:Benzazepines; D019086:Bridged Bicyclo Compounds, Heterocyclic; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; C571460:GSK923295; C098764:KIF22 protein, human; C518940:MLN8054; D011799:Quinazolines; D034741:RNA, Small Interfering; C068688:centromere protein E; C576917:AURKA protein, human; C576921:AURKB protein, human; D064096:Aurora Kinase A; D064107:Aurora Kinase B; C484228:KIF4A protein, human; D056445:Cytoplasmic Dyneins; D004398:Dyneins; D016547:Kinesins; D012521:Sarcosine