Vukušić, Kruno; Buđa, Renata; Bosilj, Agneza; Milas, Ana; Pavin, Nenad; Tolić, Iva M. (2017) Microtubule Sliding within the Bridging Fiber Pushes Kinetochore Fibers Apart to Segregate Chromosomes. Developmental Cell, 43 (1). 11-23e6. ISSN 1534-5807
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Abstract
During cell division, mitotic spindle microtubules segregate chromosomes by exerting forces on kinetochores. What forces drive chromosome segregation in anaphase remains a central question. The current model for anaphase in human cells includes shortening of kinetochore fibers and separation of spindle poles. Both processes require kinetochores to be linked with the poles. Here we show, by combining laser ablation, photoactivation, and theoretical modeling, that kinetochores can separate without any attachment to one spindle pole. This separation requires the bridging fiber, a microtubule bundle that connects sister kinetochore fibers. Bridging fiber microtubules in intact spindles slide apart with kinetochore fibers, indicating strong crosslinks between them. We conclude that sliding of microtubules within the bridging fibers drives pole separation and pushes kinetochore fibers poleward by the friction of passive crosslinks between these fibers. Thus, sliding within the bridging fiber works together with the shortening of kinetochore fibers to segregate chromosomes.
Item Type: | Article | ||||||||
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Uncontrolled Keywords: | mitotic spindle; laser ablation; kinetochore microtubules; overlap microtubules; chromosome segregation; anaphase, bridging microtubules; anaphase model; pole separation; mitosis | ||||||||
Subjects: | NATURAL SCIENCES > Physics NATURAL SCIENCES > Biology NATURAL SCIENCES > Biology > Biochemistry and Molecular Biology |
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Divisions: | Division of Molecular Biology | ||||||||
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Depositing User: | Renata Buđa | ||||||||
Date Deposited: | 19 Nov 2018 10:53 | ||||||||
URI: | http://fulir.irb.hr/id/eprint/4309 | ||||||||
DOI: | 10.1016/j.devcel.2017.09.010 |
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