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Cortical Dynein Controls Microtubule Dynamics to Generate Pulling Forces that Position Microtubule Asters

2012; Cell Press; Volume: 148; Issue: 3 Linguagem: Inglês

10.1016/j.cell.2012.01.007

1097-4172

Liedewij Laan, Nenad Pavin, Julien Husson, Guillaume Romet‐Lemonne, Martijn M. VanDuijn, Magdalena Preciado López, Ronald D. Vale, Frank Jülicher, Samara L. Reck‐Peterson, Marileen Dogterom,

Cellular Mechanics and Interactions

Dynein at the cortex contributes to microtubule-based positioning processes such as spindle positioning during embryonic cell division and centrosome positioning during fibroblast migration. To investigate how cortical dynein interacts with microtubule ends to generate force and how this functional association impacts positioning, we have reconstituted the ‘cortical’ interaction between dynein and dynamic microtubule ends in an in vitro system using microfabricated barriers. We show that barrier-attached dynein captures microtubule ends, inhibits growth, and triggers microtubule catastrophes, thereby controlling microtubule length. The subsequent interaction with shrinking microtubule ends generates pulling forces up to several pN. By combining experiments in microchambers with a theoretical description of aster mechanics, we show that dynein-mediated pulling forces lead to the reliable centering of microtubule asters in simple confining geometries. Our results demonstrate the intrinsic ability of cortical microtubule-dynein interactions to regulate microtubule dynamics and drive positioning processes in living cells.PaperClip/cms/asset/9fcccb18-2672-45c1-8192-492fb31871fe/mmc8.mp3Loading ...(mp3, 3.34 MB) Download audio