Arabidopsis formin 2 regulates cell-to-cell trafficking by capping and stabilizing actin filaments at plasmodesmata.
Arabidopsis formin 2 regulates cell-to-cell trafficking by capping and stabilizing actin filaments at plasmodesmata.
复制标题
拟南芥formin 2通过加帽和稳定胞间连丝的肌动蛋白丝来调节细胞间运输
DOI：
10.7554/elife.36316
复制
发表时间：
2018-08-16
期刊：
影响因子：
7.7
通讯作者：
Huang S
中科院分区：
文献类型：
--
作者：
Diao M;Ren S;Wang Q;Qian L;Shen J;Liu Y;Huang S
在这里，我们证明了拟南芥Forin 2(AtFH2)通过其跨膜结构域定位于胞间连丝(PD)，是正常细胞间转运所必需的。虽然丧失功能的atfh2突变体没有明显的发育缺陷，但在atfh2植株中，PD的渗透性和对病毒侵染的敏感性都增加了。有趣的是，AtFH2与其最接近的同系物AtFH1以部分冗余的方式发挥作用，AtFH1也包含PD定位信号。值得注意的是，在水稻中也证实了I类福尔明斯对PD的靶向，这表明I类福尔明斯参与调节PD的肌动蛋白动态可能在进化上是保守的。体外生化分析表明，AtFH2不能使肌动蛋白组装成核，但能封闭和稳定肌动蛋白细丝。我们还证明了AtFH2和肌动蛋白细丝之间的相互作用对其在体内的功能至关重要。这些数据允许我们提出AtFH2通过将肌动蛋白细丝锚定在PD上来调节PD的通透性。
Here, we demonstrate that Arabidopsis thaliana Formin 2 (AtFH2) localizes to plasmodesmata (PD) through its transmembrane domain and is required for normal intercellular trafficking. Although loss-of-function atfh2 mutants have no overt developmental defect, PD’s permeability and sensitivity to virus infection are increased in atfh2 plants. Interestingly, AtFH2 functions in a partially redundant manner with its closest homolog AtFH1, which also contains a PD localization signal. Strikingly, targeting of Class I formins to PD was also confirmed in rice, suggesting that the involvement of Class I formins in regulating actin dynamics at PD may be evolutionarily conserved in plants. In vitro biochemical analysis showed that AtFH2 fails to nucleate actin assembly but caps and stabilizes actin filaments. We also demonstrate that the interaction between AtFH2 and actin filaments is crucial for its function in vivo. These data allow us to propose that AtFH2 regulates PD's permeability by anchoring actin filaments to PD.