A Mechanism for Reorientation of Cortical Microtubule Arrays Driven by Microtubule Severing
A Mechanism for Reorientation of Cortical Microtubule Arrays Driven by Microtubule Severing
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DOI：
10.1126/science.1245533
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发表时间：
2013-12-06
期刊：
影响因子：
56.9
通讯作者：
Ehrhardt, David W.
中科院分区：
文献类型：
--
作者：
Lindeboom, Jelmer J.;Nakamura, Masayoshi;Ehrhardt, David W.
环境和激素信号会导致高等植物中微管阵列的重组，但驱动这些转变的机制仍然难以捉摸。这些阵列的组织是指导形态发生所必需的。我们发现，由蛋白质剑蛋白切断的微管在蓝光触发的皮质阵列重新定向中发挥着至关重要且意想不到的作用。成像和基因实验表明，向光素光感受器特别在微管交叉点刺激剑蛋白介导的切断，导致在这些位置产生新的微管。我们展示了这种活动如何作为放大与初始阵列正交的微管的机制的基础，从而驱动阵列重新定向。我们的观察显示了如何建设性地使用切断来构建新的微管阵列。
Environmental and hormonal signals cause reorganization of microtubule arrays in higher plants, but the mechanisms driving these transitions have remained elusive. The organization of these arrays is required to direct morphogenesis. We discovered that microtubule severing by the protein katanin plays a crucial and unexpected role in the reorientation of cortical arrays, as triggered by blue light. Imaging and genetic experiments revealed that phototropin photoreceptors stimulate katanin-mediated severing specifically at microtubule intersections, leading to the generation of new microtubules at these locations. We show how this activity serves as the basis for a mechanism that amplifies microtubules orthogonal to the initial array, thereby driving array reorientation. Our observations show how severing is used constructively to build a new microtubule array.