The Ndc80 kinetochore complex uses biased diffusion to couple chromosomes to dynamic microtubule tips

• Published in: Cell 2009-03, Vol.136 (5), p.865-875
• Main Authors: Powers, Andrew F., Franck, Andrew D., Gestaut, Daniel R., Cooper, Jeremy, Gracyzk, Beth, Wei, Ronnie R., Wordeman, Linda, Davis, Trisha N., Asbury, Charles L.
• Format: Article
• Language: English
• ISSN: 0092-8674; 1097-4172
• DOI: 10.1016/j.cell.2008.12.045

Kinetochores couple chromosomes to the assembling and disassembling tips of microtubules, a dynamic behavior that is fundamental to mitosis in all eukaryotes but poorly understood. Genetic, biochemical and structural studies implicate the Ndc80 complex as a direct point of contact between kinetochores and microtubules, but these approaches provide only a static view. Here, using techniques for manipulating and tracking individual molecules in vitro , we demonstrate that the Ndc80 complex is capable of forming the dynamic, load-bearing attachments to assembling and disassembling tips required for coupling in vivo . We also establish that Ndc80-based coupling likely occurs through a biased diffusion mechanism, and that this activity is conserved from yeast to humans. Our findings demonstrate how an ensemble of Ndc80 complexes may provide a ‘slip clutch’ that allows the kinetochore to maintain a load-bearing tip attachment during both microtubule assembly and disassembly.