The Human Kinesin Kif18A Is a Motile Microtubule Depolymerase Essential for Chromosome Congression
| Autor: | Tamara Grüner, Stefan Hümmer, Guenther Woehlke, Jenny Bormann, Monika I. Mayr, Thomas U. Mayer, Sarah Adio |
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| Jazyk: | angličtina |
| Předmět: |
Kinesins
Cell Cycle Proteins Microtubule Biology Microtubules Article General Biochemistry Genetics and Molecular Biology Kif18A ddc:570 Mad2 Proteins Chromosomes Human Humans Kinesin 8 Kinetochores Zellteilung Mitosis Agricultural and Biological Sciences(all) Biochemistry Genetics and Molecular Biology(all) Kinetochore Calcium-Binding Proteins Cell Cycle Mitose Chromosome Kinesin DNA Cell cycle Chromosomenbande Cell biology Repressor Proteins Mikrotubuli RNA Interference CELLBIO General Agricultural and Biological Sciences HeLa Cells |
| Zdroj: | Current Biology. (6):488-498 |
| ISSN: | 0960-9822 |
| DOI: | 10.1016/j.cub.2007.02.036 |
| Popis: | BACKGROUND:The accurate alignment of chromosomes at the spindle equator is fundamental for the equal distribution of the genome in mitosis and thus for the genetic integrity of eukaryotes. Although it is well established that chromosome movements are coupled to microtubule dynamics, the underlying mechanism is not well understood.RESULTS:By combining RNAi-depletion experiments with in vitro biochemical assays, we demonstrate that the human kinesin Kif18A is a motile microtubule depolymerase essential for chromosome congression in mammalian tissue culture cells. We show that in vitro Kif18A is a slow plus-end-directed kinesin that possesses microtubule depolymerizing activity. Notably, Kif18A like its yeast ortholog Kip3p depolymerizes longer microtubules more quickly than shorter ones. In vivo, Kif18A accumulates in mitosis where it localizes close to the plus ends of kinetochore microtubules. The depletion of Kif18A induces aberrantly long mitotic spindles and loss of tension across sister kinetochores, resulting in the activation of the Mad2-dependent spindle-assembly checkpoint. Live-cell microscopy studies revealed that in Kif18A-depleted cells, chromosomes move at reduced speed and completely fail to align at the spindle equator.CONCLUSIONS:These studies identify Kif18A as a dual-functional kinesin and a key component of chromosome congression in mammalian cells. |
| Databáze: | OpenAIRE |
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