The Schizosaccharomyces pombe EB1 homolog Mal3p binds and stabilizes the microtubule lattice seam
The Schizosaccharomyces pombe EB1 homolog Mal3p binds and stabilizes the microtubule lattice seam
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DOI：
10.1016/j.cell.2006.11.025
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发表时间：
2006-12-29
期刊：
影响因子：
64.5
通讯作者：
Hoenger, Andreas
中科院分区：
文献类型：
--
作者：
Sandblad, Linda;Busch, Karl Emanuel;Hoenger, Andreas
末端结合 1 (EB1) 蛋白是高度保守的微管动力学调节因子。使用电子显微镜 (EM) 和高分辨率表面阴影，我们研究了裂殖酵母 EB1 同源物 Mal3p 的微管结合特性。这使得可以直接观察结合在微管表面上的 Mal3p。 Mal3p 颗粒通常仅沿着相邻原丝形成的多个凹槽之一在每个微管上形成单行。我们提供的结构数据表明 Mal3p 分子的排列与微管晶格接缝一致，并且数据表明 Mal3p 不仅结合而且稳定了该接缝。因此，Mal3p 通过与微管中可能最薄弱的部分发生特定的相互作用，以一种先前未证实的方式稳定微管。我们的研究结果进一步表明，微管在其表面表现出两个不同的反应平台，可以独立地与微管相关蛋白、马达、动粒或膜等靶结构相互作用。
End binding 1 (EB1) proteins are highly conserved regulators of microtubule dynamics. Using electron microscopy (EM) and high-resolution surface shadowing we have studied the microtubule-binding properties of the fission yeast EB1 homolog Mal3p. This allowed for a direct visualization of Mal3p bound on the surface of microtubules. Mal3p particles usually formed a single line on each microtubule along just one of the multiple grooves that are formed by adjacent protofilaments. We provide structural data showing that the alignment of Mal3p molecules coincides with the microtubule lattice seam as well as data suggesting that Mal3p not only binds but also stabilizes this seam. Accordingly, Mal3p stabilizes microtubules through a specific interaction with what is potentially the weakest part of the microtubule in a way not previously demonstrated. Our findings further suggest that microtubules exhibit two distinct reaction platforms on their surface that can independently interact with target structures such as microtubule-associated proteins, motors, kinetochores, or membranes.