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The Dam1 kinetochore ring complex moves processively on depolymerizing microtubule ends
被引:220
作者:
Westermann, S
Wang, HW
Avila-Sakar, A
Drubin, DG
Nogales, E
Barnes, G
机构:
[1] Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA
[2] Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA
[3] Univ Calif Berkeley, Howard Hughes Med Inst, Berkeley, CA 94720 USA
来源:
关键词:
D O I:
10.1038/nature04409
中图分类号:
O [数理科学和化学];
P [天文学、地球科学];
Q [生物科学];
N [自然科学总论];
学科分类号:
07 ;
0710 ;
09 ;
摘要:
Chromosomes interact through their kinetochores with microtubule plus ends and they are segregated to the spindle poles as the kinetochore microtubules shorten during anaphase A of mitosis. The molecular natures and identities of coupling proteins that allow microtubule depolymerization to pull chromosomes to poles during anaphase have long remained elusive(1). In budding yeast, the ten-protein Dam1 complex is a critical microtubule-binding component of the kinetochore(2) that oligomerizes into a 50-nm ring around a microtubule in vitro(3,4). Here we show, with the use of a real-time, two-colour fluorescence microscopy assay, that the ring complex moves processively for several micrometres at the ends of depolymerizing microtubules without detaching from the lattice. Electron microscopic analysis of 'end-on views' revealed a 16-fold symmetry of the kinetochore rings. This out-of-register arrangement with respect to the 13-fold microtubule symmetry is consistent with a sliding mechanism based on an electrostatically coupled ring-microtubule interface. The Dam1 ring complex is a molecular device that can translate the force generated by microtubule depolymerization into movement along the lattice to facilitate chromosome segregation.
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页码:565 / 569
页数:5
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