Plasma-membrane protein / actin cytoskeleton interactions

质膜蛋白/肌动蛋白细胞骨架相互作用

• 批准号: BB/F014074/1
• 负责人: John Runions
• 金额: $ 40.01万
• 依托单位: Oxford Brookes University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FF014074%2F1
• 关键词: Plasma; membrane; protein; actin; cytoskeleton

Animal and plant cells are able to respond to cues from their surroundings using their protein signalling networks. Chemicals or physical sensations from outside the cell result in changes in the biochemical machinery inside the cell. Interactions of proteins are the molecular switches used by cells to respond to environmental cues. One of the primary signalling pathways in animal cells relys on the connection between proteins in the outer cell membrane and the actin cytoskeleton. Actin forms a series of filaments inside the cell membrane that support the cell and over which other proteins and organelles can move. When a receptor protein in the membrane receives a signal from outside the cell, it signals this to the actin by changing shape and this, in turn, results in activation of any of a number of cellular processes. Plant cells, like animal cells, are capable of responding to stimuli from their environment. They also have proteins in their outer membrane and an actin cytoskeleton. We don't, however, know how these membrane proteins interact with the actin. Many of the proteins have been shown in the lab to have actin binding properties but this has not been demonstrated in living cells. How will we determine if there is a physical interaction between the proteins and the actin? I have developed a technique to monitor protein movement using a confocal microscope. This type of microscope uses lasers to make a protein in the membrane of cells fluorescent. By fusing this protein - which is called Green Fluorescent Protein (GFP) - to a membrane protein I can visualise movement of the membrane protein. GFP acts as a 'marker.' The GFP I use can be activated by a short pulse of laser light enabling me to activate a small region of membrane and follow movement of the protein for longish periods of time (up to several hours). Using mathematics, I can describe the movement of the protein, i.e. its speed and direction of movement. My hypothesis is that if the protein interacts with the actin cytoskeleton then it will move differently if I destroy the cytoskeleton. There are chemicals that cause the cytoskeleton to breakdown and these can be applied to the cells so that protein movement can be measure when the cytoskeleton is absent. In addition, there are mutant plants that have defects in their actin cytoskeletons. These plants are abnormal looking as a result of improper actin structure. I predict that membrane proteins will move differently in these plants if they associagte with the abnormal actin cytoskeleton. This work will be the first step towards understanding the connection between plasma membrane and actin that is so essential in plant cell signalling.

动物和植物细胞能够利用其蛋白质信号网络对周围环境的提示做出反应。来自细胞外的化学物质或身体感觉导致细胞内生化机制的变化。蛋白质的相互作用是细胞对环境信号做出反应的分子开关。动物细胞中的主要信号传导途径之一依赖于细胞外膜中的蛋白质与肌动蛋白细胞骨架之间的连接。肌动蛋白在细胞膜内形成一系列细丝，支撑细胞，其他蛋白质和细胞器可以在其上移动。当细胞膜上的受体蛋白接收到来自细胞外的信号时，它通过改变形状将信号传递给肌动蛋白，这反过来又导致许多细胞过程中的任何一个被激活。植物细胞和动物细胞一样，能够对来自环境的刺激做出反应。它们的外膜上也有蛋白质和肌动蛋白细胞骨架。然而，我们不知道这些膜蛋白如何与肌动蛋白相互作用。许多蛋白质在实验室中已被证明具有肌动蛋白结合特性，但这尚未在活细胞中得到证实。我们如何确定蛋白质和肌动蛋白之间是否存在物理相互作用？我已经开发了一种技术来监测蛋白质运动使用共聚焦显微镜。这种类型的显微镜使用激光使细胞膜中的蛋白质发出荧光。通过将这种蛋白质--称为绿色荧光蛋白（GFP）--与膜蛋白融合，我可以看到膜蛋白的运动。GFP充当“标记”。“我使用的GFP可以被短脉冲激光激活，使我能够激活膜的一个小区域，并在较长的时间内（长达几个小时）跟踪蛋白质的运动。使用数学，我可以描述蛋白质的运动，即它的运动速度和方向。我的假设是，如果蛋白质与肌动蛋白细胞骨架相互作用，那么如果我破坏细胞骨架，它会以不同的方式移动。有一些化学物质会导致细胞骨架的破坏，这些化学物质可以应用于细胞，这样当细胞骨架缺失时，蛋白质的运动就可以被测量出来。此外，还有一些突变体植物的肌动蛋白细胞骨架有缺陷。这些植物是不正常的外观作为不正确的肌动蛋白结构的结果。我预测，如果膜蛋白与异常的肌动蛋白细胞骨架结合，它们在这些植物中的运动会不同。这项工作将是理解质膜和肌动蛋白之间的连接的第一步，这在植物细胞信号传导中至关重要。

项目成果

Recycling, clustering, and endocytosis jointly maintain PIN auxin carrier polarity at the plasma membrane.

• DOI: 10.1038/msb.2011.72
• 发表时间: 2011-10-25
• 期刊: MOLECULAR SYSTEMS BIOLOGY
• 影响因子: 9.9
• 作者: Kleine-Vehn, Juergen;Wabnik, Krzysztof;Martiniere, Alexandre;Langowski, Lukasz;Willig, Katrin;Naramoto, Satoshi;Leitner, Johannes;Tanaka, Hirokazu;Jakobs, Stefan;Robert, Stephanie;Luschnig, Christian;Govaerts, Willy;Hell, Stefan W.;Runions, John;Friml, Jiri
• 通讯作者: Friml, Jiri

Protein diffusion in plant cell plasma membranes: the cell-wall corral.

• DOI: 10.3389/fpls.2013.00515
• 发表时间: 2013
• 期刊: Frontiers in plant science
• 影响因子: 5.6
• 作者: Martinière A;Runions J
• 通讯作者: Runions J