ROLE OF THE TUBULIN E-HOOK IN THE ACTIVITY OF MICROTUBULE MOTORS

描述（由申请人提供）：我的长期目标是开展一项研究计划，研究细胞组织的分子基础。我曾在华盛顿大学John Cooper博士的实验室接受博士后培训，在那里我研究了微管运动动力蛋白。所有真核生物都利用微管马达（如动力蛋白）来组织细胞内环境，以协调细胞结构和形态的变化。这些情况包括在细胞分裂过程中基因组的分裂，细胞内蛋白质和细胞器的运输，以及可能所有形式的细胞迁移。尽管微管电机在这些过程中起着核心作用，但人们对电机如何与微管衬底相互作用以产生力知之甚少。根据本提案中概述的研究，我将开发新的体内和体外系统，以研究微管的结构特征如何影响运动活动。这些工具的开发对于我计划在自己的实验室中进行的独立研究项目至关重要。本提案的主要目的是验证a-微管蛋白亚基上带负电荷的E-hook基序通过促进微管马达的结合和/或运动性来促进微管功能的假设，并确定该基序的作用是否在进化上不同类别的马达中有所不同。我将特别关注动力蛋白马达，并试图确定动力蛋白与E-hook基序相互作用的分子基础和后果。本项目将通过追求两个目标来解决这些问题：目标1。微管蛋白E-hook是否能促进体内微管马达的活性？目标2。E-hook突变时动力蛋白运动的直接分析。总之，这些分析将提高我们对微管功能的理解，并可能证明对人类疾病的治疗有用。微管运动参与许多疾病，包括神经元病理和肿瘤发生；因此，了解运动-微管相互作用的分子细节可能会导致通过调节特定运动的活性来改变细胞功能的治疗。

DESCRIPTION (provided by applicant): My long-term goal is to conduct a research program that examines the molecular basis of cellular organization. I have received postdoctoral training in the lab of Dr. John Cooper at Washington University, where I have studied the microtubule motor dynein. All eukaryotes employ microtubule motors such as dynein to organize the intracellular environment in coordination with changes in cell structure and morphology. These scenarios include partitioning the genome during cell division, intracellular transport of proteins and organelles, and perhaps all forms of cell migration. Despite the central role for micortubule motors in these processes, how motors interact with the microtubule substrate in order to produce force is poorly understood. With the research outlined in this proposal, I will develop novel in vivo and in vitro systems to examine how structural features on the microtubule influence motor activity. The development of these tools will be critical for the independent research program that I plan to pursue in my own lab. The broad objective of this proposal is to test the hypothesis that the negatively-charged E-hook motif on the a-tubulin subunit contributes to microtubule function by promoting the binding and/or motility of microtubule motors, and determine whether the role of this motif differs for evolutionarily distinct classes of motors. I will particularly focus on the dynein motor, and seek to identify the molecular basis and consequences of dynein's interaction with the E-hook motif. This project will address these issues by pursuing two aims: Aim 1. Does the tubulin E-hook promote the activity of microtubule motors in vivo? Aim 2. Direct analysis of dynein motility in the presence of the E-hook mutations. Together these analyses will improve our understanding of microtubule function, and may proove useful for the treatment of human disease. Microtubule motors are involved in many diseases, including neuronal pathologies and tumorigenesis; therefore, understanding the molecular details of motor-microtubule interactions may lead to therapies aimed at altering cellular function by modulating the activity of specific motors. PUBLIC HEALTH RELEVANCE: This project will broaden our understanding of how microtubule motors function, and identify novel pharmacological agents that inhibit dynein activity. This is relevant to human health because he functions of motora are critical to the organization and function of cells. Defects in motor function are known to cause specific diseases, particularly neurological disorders, but the molecular basis of how motor dysfunction contributes to pathology is not understood. Additionally, motors contribute to the progression of other diseases, such as viral infections and tumorigenesis; therefore, understanding the molecular details of motor function will inform strategies for developing effective therapeutics.