Successive Kinesin-5 Microtubule Crosslinking and Sliding Promote Fast, Irreversible Formation of a Stereotyped Bipolar Spindle
Autor: | Kristian Shulist, Shannon Sim, Rachel Genthial, Khanh Huy Bui, Allen Leary, Jackie Vogel, Paul François, Elena Nazarova, Shun Kai Yang |
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Rok vydání: | 2019 |
Předmět: |
0301 basic medicine
Saccharomyces cerevisiae Proteins Cell division Kinesins Mitosis macromolecular substances Saccharomyces cerevisiae Spindle Apparatus Biology Microtubules General Biochemistry Genetics and Molecular Biology Spindle pole body 03 medical and health sciences 0302 clinical medicine Microtubule Spindle Poles Cell Cycle Microtubule sliding Spindle apparatus 030104 developmental biology Biophysics Kinesin General Agricultural and Biological Sciences Multipolar spindles 030217 neurology & neurosurgery |
Zdroj: | Current biology : CB. 29(22) |
ISSN: | 1879-0445 |
Popis: | Separation of duplicated spindle poles is the first step in forming the mitotic spindle. Kinesin-5 crosslinks and slides anti-parallel microtubules (MTs), but it is unclear how these two activities contribute to the first steps in spindle formation. In this study, we report that in monopolar spindles, the duplicated spindle poles snap apart in a fast and irreversible step that produces a nascent bipolar spindle. Using mutations in Kinesin-5 that inhibit microtubule sliding, we show that the fast, irreversible pole separation is primarily driven by microtubule crosslinking. Electron tomography revealed microtubule pairs in monopolar spindles have short overlaps that intersect at high angles and are unsuited for ensemble Kinesin-5 sliding. However, maximal extension of a subset of anti-parallel microtubule pairs approaches the length of nascent bipolar spindles and is consistent with a Kinesin-5 crosslinking-driven transition. Nonetheless, microtubule sliding by Kinesin-5 contributes to stabilizing the nascent spindle and setting its stereotyped equilibrium length. |
Databáze: | OpenAIRE |
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