@article {3631,
	title = {Tension directly stabilizes reconstituted kinetochore-microtubule attachments.},
	journal = {Nature},
	volume = {468},
	year = {2010},
	month = {2010 Nov 25},
	pages = {576-9},
	abstract = {<p>Kinetochores are macromolecular machines that couple chromosomes to dynamic microtubule tips during cell division, thereby generating force to segregate the chromosomes. Accurate segregation depends on selective stabilization of correct {\textquoteright}bi-oriented{\textquoteright} kinetochore-microtubule attachments, which come under tension as the result of opposing forces exerted by microtubules. Tension is thought to stabilize these bi-oriented attachments indirectly, by suppressing the destabilizing activity of a kinase, Aurora B. However, a complete mechanistic understanding of the role of tension requires reconstitution of kinetochore-microtubule attachments for biochemical and biophysical analyses in vitro. Here we show that native kinetochore particles retaining the majority of kinetochore proteins can be purified from budding yeast and used to reconstitute dynamic microtubule attachments. Individual kinetochore particles maintain load-bearing associations with assembling and disassembling ends of single microtubules for \&gt;30 min, providing a close match to the persistent coupling seen in vivo between budding yeast kinetochores and single microtubules. Moreover, tension increases the lifetimes of the reconstituted attachments directly, through a catch bond-like mechanism that does not require Aurora B. On the basis of these findings, we propose that tension selectively stabilizes proper kinetochore-microtubule attachments in vivo through a combination of direct mechanical stabilization and tension-dependent phosphoregulation.</p>
},
	keywords = {Chromosomes, Fungal Proteins, Kinetochores, Microtubules, Saccharomyces cerevisiae},
	issn = {1476-4687},
	doi = {10.1038/nature09594},
	author = {Akiyoshi, Bungo and Sarangapani, Krishna K and Powers, Andrew F and Nelson, Christian R and Reichow, Steve L and Arellano-Santoyo, Hugo and Gonen, Tamir and Ranish, Jeffrey A and Asbury, Charles L and Biggins, Sue}
}
@article {45961,
	title = {Tension applied through the Dam1 complex promotes microtubule elongation providing a direct mechanism for length control in mitosis.},
	journal = {Nature Cell Biology},
	volume = {9},
	year = {2007},
	month = {2007 Jul},
	pages = {832-7},
	abstract = {<p>In dividing cells, kinetochores couple chromosomes to the tips of growing and shortening microtubule fibres and tension at the kinetochore-microtubule interface promotes fibre elongation. Tension-dependent microtubule fibre elongation is thought to be essential for coordinating chromosome alignment and separation, but the mechanism underlying this effect is unknown. Using optical tweezers, we applied tension to a model of the kinetochore-microtubule interface composed of the yeast Dam1 complex bound to individual dynamic microtubule tips. Higher tension decreased the likelihood that growing tips would begin to shorten, slowed shortening, and increased the likelihood that shortening tips would resume growth. These effects are similar to the effects of tension on kinetochore-attached microtubule fibres in many cell types, suggesting that we have reconstituted a direct mechanism for microtubule-length control in mitosis.</p>
},
	keywords = {Biomechanical Phenomena, Cell Cycle Proteins, Fungal Proteins, Kinetochores, Microspheres, Microtubule-Associated Proteins, Microtubules, Mitosis, Optical Tweezers, Saccharomyces cerevisiae Proteins},
	issn = {1465-7392},
	doi = {10.1038/ncb1609},
	author = {Franck, Andrew D and Powers, Andrew F and Gestaut, Daniel R and Gonen, Tamir and Davis, Trisha N and Asbury, Charles L}
}
