van Breugel Mark, Drechsel David, Hyman Anthony
Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.
J Cell Biol. 2003 Apr 28;161(2):359-69. doi: 10.1083/jcb.200211097.
The Dis1/XMAP215 family of microtubule-associated proteins conserved from yeast to mammals is essential for cell division. XMAP215, the Xenopus member of this family, has been shown to stabilize microtubules in vitro, but other members of this family have not been biochemically characterized. Here we investigate the properties of the Saccharomyces cerevisiae homologue Stu2p in vitro. Surprisingly, Stu2p is a microtubule destabilizer that binds preferentially to microtubule plus ends. Quantitative analysis of microtubule dynamics suggests that Stu2p induces microtubule catastrophes by sterically interfering with tubulin addition to microtubule ends. These results reveal both a new biochemical activity for a Dis1/XMAP215 family member and a novel mechanism for microtubule destabilization.
从酵母到哺乳动物保守的微管相关蛋白Dis1/XMAP215家族对细胞分裂至关重要。该家族的非洲爪蟾成员XMAP215已被证明在体外能稳定微管，但该家族的其他成员尚未进行生化特性分析。在这里，我们在体外研究酿酒酵母同源物Stu2p的特性。令人惊讶的是，Stu2p是一种微管去稳定剂，它优先结合微管正端。对微管动力学的定量分析表明，Stu2p通过空间位阻干扰微管蛋白添加到微管末端而诱导微管灾变。这些结果揭示了Dis1/XMAP215家族成员的一种新的生化活性以及微管去稳定的一种新机制。
