An Orphaned Kinesin with a Leading Role in Plant Cell Morphogenesis

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。在植物发育过程中，植物细胞经历了一系列高度协调的细胞分裂和伸长事件，这些事件直接影响了成年植物的形状。细胞分裂和伸长的中心是微管，微管是作为引导和运输轨道的亚细胞元件。驱动蛋白是一类与微管相互作用的细胞马达，用于帮助细胞组分的运输并影响微管本身的功能和构型。进化的力量以不同的方式作用于祖先的驱动蛋白马达，以至于现在在所有真核细胞中识别出15个亚家族。即将进行的研究将调查一种称为ATKINUA的驱动蛋白在植物发育过程中如何影响生长和发育。遗传证据表明，ATKINUA是所有器官中最基本的早期发育所必需的，即茎顶端分生组织（容纳产生植物所有气生部分的细胞），以及更多衍生的组织和细胞，包括叶气孔（参与气体交换和水分调节）。将进行实验以分离和表征不正常表达这种蛋白质的植物，这将提供对它通常如何发挥作用的深入了解。将使用转基因植物进行额外的实验，其中荧光蛋白被工程化到ATKINUA中;这将使研究人员能够在发育过程中观察活细胞中的这种驱动蛋白。由于这种驱动蛋白显示出与微管阵列的优先关联，有助于确定细胞分裂的平面，研究人员将工程突变到驱动蛋白中，可以预见的是，这种突变会破坏这种定位;这种错误靶向的驱动蛋白的影响将在转基因植物中进行研究。对这种驱动蛋白的生物信息学分析表明，它具有与细胞中的信号传导部分相互作用的潜力。因此，将进行一系列实验以鉴定其相互作用蛋白;研究人员预计，这些相互作用蛋白的鉴定将导致进一步的实验，旨在了解植物细胞如何整合这种驱动蛋白的活性，以影响正常的植物生长和发育。更广泛的影响植物构成了所有农业活动的基础，因此，如果研究人员要在改良作物方面进行战略性努力，了解促进其正常发育的基本机制至关重要。该项目旨在提供有助于这一战略努力的信息。该项目还将为两个重要的青年科学家群体提供培训。首先，博士后研究人员将接受现代细胞生物学方法的培训，这将使此人能够建立和开展对国家科学活力至关重要的未来研究。此外，此人将接受课堂教学培训，这将提高他或她在未来学术职位上的教学效率。第二，谁是在一个预科水平的细胞和分子生物学课程注册的本科生将受益于这个项目。这些学生将参加实验，以确定ATKINUA的相互作用蛋白质。这一经验的预期结果将是科学研究的兴奋点。课程结束后，将为感兴趣的学生提供继续研究的机会。可能，通过这种经验，一个或多个学生将决定选择在科学的职业道路。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).During plant development, plant cells undergo a highly orchestrated series of cell divisions and elongation events that contribute directly to the shape of the adult plant. Central to both cell division and elongation are microtubules, which are subcellular elements that act as guides and transport rails. Kinesins are a class of cellular motors that interact with microtubules and serve to assist in both transport of cellular components and to affect the function and configuration of microtubules themselves. Evolutionary forces have acted upon the ancestral kinesin motor in diverse ways, to the extent that 15 subfamilies are now recognized throughout all eukaryotic cells. The research to be carried out will investigate how one kinesin, termed ATKINUA, acts during plant development to affect growth and development. Genetic evidence indicates ATKINUA is absolutely required for early development in the most basal of all organs, the shoot apical meristem (which houses the cells that give rise to all aerial portions of the plant), and in more derived tissues and cells, including leaf stomata (which are involved in gas exchange and water regulation). Experiments will be carried out to isolate and characterize plants that do not express this protein normally, and this will provide insight into how it usually functions. Additional experiments will be carried out using transgenic plants in which a fluorescent protein is engineered into ATKINUA; this will enable the researchers to visualize this kinesin in living cells during development. Because this kinesin shows preferential association with the microtubule array that assists in determining the plane of cell division, the researchers will engineer mutations into the kinesin that predictably should disrupt this localization; the effects of this mis-targeted kinesin will be studied in transgenic plants. Bioinformatic analysis of this kinesin indicates it has the potential to interact with signaling moieties in the cell. Therefore, a series of experiments will be carried out to identify its interacting proteins; the researchers anticipate the identification of these interacting proteins will lead to further experiments aimed at understanding how plant cells integrate the activity of this kinesin to affect normal plant growth and development.Broader ImpactsPlants comprise the foundation for all agricultural activities, so understanding the basic mechanisms that facilitate their normal development is critical if researchers are to pursue a strategic effort in improving crops. This project seeks to provide information that will contribute to such a strategic effort. The project will also provide training for two critical groups of young scientists. First, a postdoctoral researcher will be trained in modern cell biological methods, which will enable the person to establish and carry out future research that is critical for the country's scientific vitality. In addition, this person will receive training in classroom instruction, which will enhance his or her teaching effectiveness in a future academic position. Second, undergraduate students who are enrolled in a sophomore-level cell and molecular biology course will benefit from this project. These students will participate in the experiments to identify interacting proteins of ATKINUA. The anticipated outcome of this experience will be an excitement for scientific research. Opportunities will be provided, after the class is completed, for interested students to continue with the research. Possibly, through this experience, one or more students will decide to choose a career path in science.