Role of a Small GTPase in Coordinating Two Motility Systems

爱达荷州大学的Hartzell博士获得了一笔赠款，用于研究细菌细胞在表面上滑动所需的蛋白质。 用于这些研究的模型细菌，黄色粘球菌，同时使用两种不相关的马达来推动自己。一个马达使用纤维拉动细胞，而另一个马达释放推动细胞的材料。 每个马达系统具有用于向前和向后运动的部件。虽然最近的研究已经阐明了这两种运动机制，但当运动方向切换时，这两种不同的运动系统协调的过程知之甚少。Hartzell博士和她的学生已经确定了似乎在运动转换途径中发挥作用的蛋白质。他们正在使用生物化学，遗传学和分子方法来研究两个马达同步产生相同方向推力并同时逆转其方向的机制。最初的工作将集中在了解MglA，一个小的GTP结合蛋白，和它的合作伙伴，MasK，酪氨酸激酶蛋白之间的相互作用。该项目将支持对两名研究生和几名本科生进行生物系统方面的科学培训。首席研究员积极鼓励年轻女性和代表性不足的群体的学生加入她的实验室。这些学生将研究的蛋白质与动物细胞生长和发育所必需的蛋白质有关。Ras和MglA都与其他蛋白质（包括酪氨酸激酶）相互作用，以调节关键的细胞过程。然而，在高度保守的细菌和人类GTP结合蛋白和酪氨酸激酶之间有几个基本的差异，这些差异只是最近才被揭示出来。因此，这些研究有望为这些必需蛋白质的功能和进化以及它们控制的复杂途径提供重要线索。

A grant has been awarded to Dr. Hartzell at the University of Idaho to study proteins that are required for gliding movement of bacterial cells on surfaces. The model bacterium used for these studies, Myxococcus xanthus, uses two unrelated types of motors simultaneously to propel itself. One motor uses a fiber to pull the cell while the other motor releases a material that pushes the cell. Each motor system has a component for forward and reverse motion. Although recent studies have elucidated the two motor mechanisms, little is known about the process by which the two different motor systems are coordinated when the direction of movement switches. Dr. Hartzell and her students have identified proteins that appear to play a role in the motor switching pathway. They are using biochemical, genetic, and molecular approaches to investigate the mechanism by which the two motors are synchronized to generate thrust in the same direction and to reverse their orientation simultaneously. Initial work will focus on understanding the interactions between MglA, a small GTP-binding protein, and its partner, MasK, a tyrosine kinase protein. This project will support the scientific training of two graduate and several undergraduate students in biological systems. The lead investigator has actively encouraged young women and students of underrepresented groups to join her lab. The proteins that these students will study are related to proteins that are essential for growth and development of animal cells. Both Ras and MglA interact with other proteins, including tyrosine kinases, to regulate critical cellular processes. However, there are several fundamental differences between the highly conserved bacterial and human GTP-binding proteins and tyrosine kinases that only recently have been revealed. Hence these studies promise to provide important clues to the function and evolution of these essential proteins and the complex pathways they control.