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，植物细胞经历一系列高度协调的细胞分裂和伸长事件，直接影响成体植物的形状。细胞分裂和伸长的中心是微管，它是亚细胞元件，起引导和运输轨道的作用。运动蛋白是一类与微管相互作用的细胞马达，有助于细胞成分的运输，并影响微管本身的功能和结构。进化的力量以不同的方式作用于祖先的运动蛋白，以至于现在在所有真核细胞中都发现了15个亚家族。即将开展的研究将调查一种名为ATKINUA的驱动蛋白在植物发育过程中如何影响生长发育。遗传证据表明，ATKINUA是所有器官中最基础的早期发育所必需的，包括茎尖分生组织（它容纳了产生植物所有空气部分的细胞），以及更多的衍生组织和细胞，包括叶气孔（参与气体交换和水分调节）。将进行实验来分离和表征不正常表达这种蛋白质的植物，这将有助于了解它通常是如何起作用的。将使用转基因植物进行更多实验，其中将荧光蛋白植入ATKINUA；这将使研究人员能够在活细胞发育过程中可视化这种驱动蛋白。由于这种驱动蛋白与帮助确定细胞分裂平面的微管阵列表现出优先关联，研究人员将在驱动蛋白中设计突变，可预测地破坏这种定位；这种错误靶向的驱动蛋白的作用将在转基因植物中进行研究。该激酶的生物信息学分析表明，它具有与细胞中的信号分子相互作用的潜力。因此，将进行一系列的实验来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，从而影响正常的植物生长和发育。更广泛的影响植物是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，了解促进植物正常发育的基本机制是至关重要的。本项目旨在提供有助于这种战略努力的信息。该项目还将为两个关键的青年科学家群体提供培训。首先，博士后研究员将接受现代细胞生物学方法的培训，这将使他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的培训，这将提高他或她在未来学术岗位上的教学效率。第二，选修大二细胞与分子生物学课程的本科生将受益于本项目。这些学生将参与鉴定ATKINUA相互作用蛋白的实验。这一经验的预期结果将使科学研究兴奋不已。课程结束后，将为感兴趣的学生提供继续研究的机会。有可能，通过这次经历，一个或多个学生将决定选择科学的职业道路。

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.