Arabidopsis microtubule-associated protein AtMAP65-2 acts as a microtubule stabilizer
Arabidopsis microtubule-associated protein AtMAP65-2 acts as a microtubule stabilizer
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DOI：
10.1007/s11103-008-9426-1
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发表时间：
2009-02-01
影响因子：
5.1
通讯作者：
Mao, Tong-Lin
中科院分区：
文献类型：
--
作者：
Li, Hua;Zeng, Xian;Mao, Tong-Lin
在拟南芥基因组中已经鉴定出9个编码MAP65家族蛋白的基因。在这项研究中，我们报道了AtMAP65家族成员AtMAP65-2可以强稳定微管（MTs）。细菌表达的AtMAP65-2融合蛋白在体外诱导大MT束的形成。虽然AtMAP65-2对MT组装或成核的影响很小，但在体外低温处理下，AtMAP65-2对MT有很大的稳定作用。对截断的AtMAP65-2的分析表明，包含495-578氨基酸的区域，形成了一个灵活的延伸环，在MTs的稳定中起着至关重要的作用。对表达AtMAP65-2- gfp融合蛋白的悬浮培养拟南芥细胞的分析表明，在整个细胞周期中，AtMAP65-2与MTs共定位。用AtMAP65-2-GFP修饰的皮质mt在体内对破坏mt的药物丙酰胺和冰处理更具抗性。本研究结果表明，AtMAP65-2具有很强的稳定性，并参与了MT组织和动态的调节。
Nine genes that encode proteins of the MAP65 family have been identified in the Arabidopsis thaliana genome. In this study, we reported that AtMAP65-2, a member of the AtMAP65 family, could strongly stabilize microtubules (MTs). Bacterially-expressed AtMAP65-2 fusion proteins induced the formation of large MT bundles in vitro. Although AtMAP65-2 showed little effect on MT assembly or nucleation, AtMAP65-2 greatly stabilized MTs that were subjected to low-temperature treatment in vitro. Analyses of truncated versions of AtMAP65-2 indicated that the region that encompassed amino acids 495-578, which formed a flexible extended loop, played a crucial role in the stabilization of MTs. Analysis of suspension-cultured Arabidopsis cells that expressed the AtMAP65-2-GFP fusion protein showed that AtMAP65-2 co-localized with MTs throughout the cell cycle. Cortical MTs that were decorated with AtMAP65-2-GFP were more resistant to the MT-disrupting drug propyzamide and to ice treatment in vivo. The results of this study demonstrate that AtMAP65-2 strongly stabilizes MTs and is involved in the regulation of MT organization and dynamics.