AtFH8 is involved in root development under effect of low-dose latrunculin B in dividing cells.
AtFH8 is involved in root development under effect of low-dose latrunculin B in dividing cells.
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DOI：
10.1093/mp/ssq085
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发表时间：
2011-03
期刊：
影响因子：
27.5
通讯作者：
Xiuhua Xue;Chun Guo;Fei Du;Q. Lu;Chuan-Mao Zhang;H. Ren
中科院分区：
文献类型：
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作者：
Xiuhua Xue;Chun Guo;Fei Du;Q. Lu;Chuan-Mao Zhang;H. Ren
Formins因其具有较强的成核活性而备受关注。然而，AtFHs的体内功能和它们对肌动蛋白组织的影响之间的联系还不是很清楚。在本研究中，我们对AtFH8的体外和体内结合活性进行了表征。生化分析表明，在肌动蛋白聚合过程中，AtFH8(FH1FH2)可形成二聚体并捆绑预先形成的肌动蛋白细丝或诱导星状结构。截短型AtFH8的表达和免疫定位分析表明，AtFH8主要定位于间期核膜和胞质分裂后的新细胞壁，主要依赖于其N端跨膜结构域。GUS组织化学染色表明，AtFH8主要在拟南芥的根分生组织、维管系统和侧根的突起部位表达。Latrunculin B(LatB)能抑制atfh8的初生根生长和侧根发生。对拟南芥根尖分裂细胞数量的分析表明，Lat B处理的atfh8植株的分裂细胞数量明显少于野生型植株，这表明atFH8参与了细胞分裂。Atfh8-1根分生组织中的肌动蛋白细胞骨架对LatB处理比野生型更敏感。综上所述，我们的结果表明，AtFH8是一种肌动蛋白细丝核仁和束状蛋白，在细胞分裂和根发育中发挥作用。
Formins have been paid much attention for their potent nucleating activity. However, the connection between the in vivo functions of AtFHs (Arabidopsis thaliana formin homologs) and their effects on actin organization is poorly understood. In this study, we characterized the bundling activity of AtFH8 in vitro and in vivo. Biochemical analysis showed that AtFH8(FH1FH2) could form dimers and bundle preformed actin filaments or induce stellar structures during actin polymerization. Expression of truncated forms of AtFH8 and immunolocalization analysis showed that AtFH8 localized primarily to nuclear envelope in interphase and to the new cell wall after cytokinesis, depending primarily on its N-terminal transmembrane domain. GUS histochemical staining showed AtFH8 was predominantly expressed in Arabidopsis root meristem, vasculature, and outgrowth points of lateral roots. The primary root growth and lateral root initiation of atfh8 could be decreased by latrunculin B (LatB). Analysis of the number of dividing cells in Arabidopsis root tips showed that much fewer dividing cells in Lat B-treated atfh8 plants than wild-type plants, which indicates that AtFH8 was involved in cell division. Actin cytoskeleton in root meristem of atfh8-1 was more sensitive to LatB treatment than that of wild-type. Altogether, our results indicate that AtFH8 is an actin filament nucleator and bundler that functions in cell division and root development.