ROP GTPase-dependent actin microfilaments promote PIN1 polarization by localized inhibition of clathrin-dependent endocytosis.
ROP GTPase-dependent actin microfilaments promote PIN1 polarization by localized inhibition of clathrin-dependent endocytosis.
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DOI：
10.1371/journal.pbio.1001299
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发表时间：
2012
期刊：
影响因子：
9.8
通讯作者：
Yang Z
中科院分区：
文献类型：
--
作者：
Nagawa S;Xu T;Lin D;Dhonukshe P;Zhang X;Friml J;Scheres B;Fu Y;Yang Z
在叶表皮铺装细胞中的一项研究表明，生长素激活植物的Rho样GTdR通过网格蛋白介导的途径，通过调节皮质F-肌动蛋白的积累，诱导内吞作用的抑制。通过结构或分子的不对称分布的细胞极化对于不同的细胞功能和生物体的发育是必不可少的，但极性如何发育控制一直知之甚少。在植物中，参与典型植物激素生长素的细胞外排的PIN形成（PIN）蛋白的不对称分布在发育模式、形态发生和差异生长中起着中心作用。最近，我们发现生长素通过激活叶表皮铺装细胞中的Rho家族ROP GTP酶来促进细胞交错。在这里，我们发现，生长素激活的ROP 2信号通路调节不对称分布的PIN 1抑制其内吞作用。ROP 2通过由ROP 2效应蛋白RIC 4诱导的皮质肌动蛋白微丝的积累来抑制PIN 1内吞作用。我们的研究结果表明，通过Rho依赖的细胞骨架重组的发育生长素信号和极性PIN 1分布之间的联系，并揭示了基于Rho GTP酶介导的内吞抑制的细胞极化的设计原则的保护。细胞极性的形成是以不对称方式分布细胞结构或分子的过程。这个过程在产生不同的细胞形式和类型中起着重要作用。在植物中，典型的激素生长素对多种生理功能，包括细胞和器官的生长和发育都很重要。为了实现这些功能，生长素必须被运输并定位到植物内的特定区域。这部分地由PIN形成的（PIN）生长素外排转运蛋白的极性分布介导，其将生长素转运到细胞外并允许生长素在整个植物组织和器官中定向短距离和长距离转运。虽然生长素本身被认为是调节PIN极性分布的信号，但生长素是如何做到这一点的仍有待阐明。我们以前表明，生长素促进叶表皮铺装细胞，其中包含叉指状叶和压痕的“拼图”极性的产生，通过激活保守的Rho家族的小GTPases的ROP（Rho样GTPases从植物）成员。在这里，我们发现肺叶区域中生长素依赖性的ROP 2局部激活抑制了PIN 1内化到内体隔室（或内吞作用），从而使肺叶区域中PIN 1极性分布水平更高。通过ROP 2效应蛋白RIC 4（一种参与细胞骨架重塑的蛋白质）改变肌动蛋白细胞骨架，从而抑制PIN 1内化。我们的研究结果的基础上，我们提出，Rho GTP酶介导的抑制内吞的PIN 1提供了一个自组织机制的极性PIN 1分布。基于Rho GTP酶的内吞作用抑制对于动物细胞中细胞极性的形成也是重要的。因此，我们得出结论，Rho GT3信号抑制内吞作用是一种常见的机制，在多细胞生物体中的细胞极化。
A study in leaf epidermal pavement cells reveals that auxin activation of a Rho-like GTPase from plants induces inhibition of endocytosis through the clathrin-mediated pathway by regulating the accumulation of cortical F-actin. Cell polarization via asymmetrical distribution of structures or molecules is essential for diverse cellular functions and development of organisms, but how polarity is developmentally controlled has been poorly understood. In plants, the asymmetrical distribution of the PIN-FORMED (PIN) proteins involved in the cellular efflux of the quintessential phytohormone auxin plays a central role in developmental patterning, morphogenesis, and differential growth. Recently we showed that auxin promotes cell interdigitation by activating the Rho family ROP GTPases in leaf epidermal pavement cells. Here we found that auxin activation of the ROP2 signaling pathway regulates the asymmetric distribution of PIN1 by inhibiting its endocytosis. ROP2 inhibits PIN1 endocytosis via the accumulation of cortical actin microfilaments induced by the ROP2 effector protein RIC4. Our findings suggest a link between the developmental auxin signal and polar PIN1 distribution via Rho-dependent cytoskeletal reorganization and reveal the conservation of a design principle for cell polarization that is based on Rho GTPase-mediated inhibition of endocytosis. Formation of cell polarity is a process of distributing cellular structures or molecules in an asymmetric manner. This process plays an important role in the generation of diverse cell forms and types. In plants, the quintessential hormone auxin is important for diverse physiological functions, including growth and development of cells and organs. To perform these functions, auxin must be transported and localized to specific regions within the plant. This is partially mediated by polar distribution of the PIN-FORMED (PIN) auxin efflux transporters, which transport auxin outside of the cell and allow for the directional short- and long-distance transport of auxin throughout plant tissues and organs. Although auxin itself has been implicated as a signal to regulate PIN polar distribution, how auxin does so remains to be elucidated. We previously showed that auxin promotes the generation of “puzzle-piece” polarity in leaf epidermal pavement cells, which contain interdigitated lobes and indentations, by activating the ROP (Rho-like GTPases from plants) members of the conserved Rho family of small GTPases. Here, we find that auxin-dependent local activation of ROP2 in the lobe region inhibits PIN1 internalization into the endosomal compartments (or endocytosis), leaving higher levels of PIN1 polar distribution in the lobe region. PIN1 internalization is inhibited by altering the actin cytoskeleton through the ROP2 effector protein RIC4, a protein involved in cytoskeletal remodeling. On the basis of our findings, we propose that the Rho GTPase-mediated inhibition of endocytosis of PIN1 provides a self-organizing mechanism for the polar PIN1 distribution. Rho GTPase-based inhibition of endocytosis is also important for the formation of cell polarity in animal cells. Thus, we conclude that Rho GTPase signaling to inhibit endocytosis is a common mechanism for cell polarization in multicellular organisms.
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影响因子：
3.3
作者：
Bloch, D;Lavy, M;Yalovsky, S
通讯作者：
Yalovsky, S
影响因子：
64.5
作者：
Geldner, N;Anders, N;Jürgens, G
通讯作者：
Jürgens, G
影响因子：
9.2
作者：
Heisler, MG;Ohno, C;Meyerowitz, EM
通讯作者：
Meyerowitz, EM
DOI：
10.1016/j.cub.2009.08.052
发表时间：
2009-11-17
期刊：
Current biology : CB
影响因子：
--
作者：
Fu Y;Xu T;Zhu L;Wen M;Yang Z
通讯作者：
Yang Z
影响因子：
9.8
作者：
Hazak O;Bloch D;Poraty L;Sternberg H;Zhang J;Friml J;Yalovsky S
通讯作者：
Yalovsky S