The Biochemical Basis for the Mechanics of Cytokinesis

细胞分裂机制的生化基础

基本信息

批准号：
7648310
负责人：
DOUGLAS N ROBINSON
金额：
$ 33.62万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2003
资助国家：
美国
起止时间：
2003-08-01 至 2013-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7648310
关键词：
Actins Affect Aneuploidy Antineoplastic Agents Behavior Biochemical Cell Adhesion Cell Cycle Cell Shape Cell division Cell physiology Cells Computer Architectures Crosslinker Cytokinesis Cytoskeletal Modeling Data Daughter Dependency Disease Dissection Drosophila polo protein Drug Delivery Systems Event Evolution Failure Genes Genetic Goals Grant Human Image Lead Life Link Malignant Neoplasms Measures Mechanical Stress Mechanics Mediating Microtubules Modeling Molecular Mothers Myosin Type II Nocodazole Normal Cell Pathway interactions Plasmids Process Property Proteins RNA-Binding Proteins Race Regulatory Pathway Shapes Signal Transduction Source Specificity Stress Structure System Testing Tetraploidy Tumor Suppressor Genes Work aurora kinase base cancer cell cancer therapy cell growth chemical genetics clinical application crosslink daughter cell gene function in vivo inhibitor/antagonist inner centromere protein interest loss of function mutant novel particle physical property public health relevance reconstitution response small molecule tumor

项目摘要

DESCRIPTION (provided by applicant): Cytokinesis, the separation of a mother cell into two daughters, is an essential life process. Cytokinesis failure leads to tetraploidy then aneuploidy, an early event in tumor formation. We have been striving to understand how cells use proteins to generate the relevant cellular physical properties that drive cytokinesis contractility. We are also interested in developing small molecule inhibitors to aid in gene function identification and pathway dissection, but with the ultimate goal that some of these small molecule inhibitors will have clinical applications. In this proposal, we will build on the analytical framework that we initiated in the first cycle of the grant, but we will also expand our effort in several ways. In Aim 1, we will measure the lifetimes of myosin-II and various actin crosslinkers in different mutant backgrounds where the mechanics are known in order to assess the consequences of mechanical strain on crosslinker lifetimes. We will test our understanding of the molecular control of cytokinesis mechanics and dynamics by measuring cortical mechanics of dividing mutant strains where we have specific predictions of the mechanics. We will also begin studying lower hierarchical levels of cytoskeletal function by reconstituting crosslinked actin networks, applying mechanical strain to them, and studying the behavior of the crosslinkers and the network. We will use either FRAP or single particle analysis to assess the strain dependency of crosslinker lifetimes; we have several predictions based on our in vivo studies. In Aim 2, we will draw upon our observations that RacE is responsible for generating resistive stresses during cytokinesis and for restricting the mechanosensory system that we discovered to cytokinesis. In this Aim, we will identify RacE effectors to flesh out this pathway. We will study 14-3-3, which was identified as a suppressor of nocodazole. Genetic interactions between RacE and 14-3-3 further point towards a pathway in which microtubules regulate RacE and/or 14-3-3, which in turn regulate global actin crosslinkers to control the dynamics and mechanics of cytokinesis contractility. In Aim 3, we will expand our molecular inquiry by identifying the affected genes in the REMI mutants we have already recovered. PUBLIC HEALTH RELEVANCE: Of great importance for normal cell growth and disease processes such as cancer, cytokinesis has the promise of providing a rich source of new anti-cancer drug targets. We are striving to understand how cytokinesis works at a fundamental level and how the cell uses proteins to generate the physical features of contractility. Ultimately, with a rigorous understanding and a complete molecular handle on the process, it should be possible to develop better cancer therapies that are tailored to the properties of specific types of cancer cells.

描述（由申请人提供）：将母细胞分为两个女儿的细胞因子是一个重要的生活过程。细胞因子衰竭导致四倍体，然后导致非整倍性，这是肿瘤形成的早期事件。我们一直在努力了解细胞如何使用蛋白质生成驱动细胞因子收缩力的相关细胞物理特性。我们还有兴趣开发小分子抑制剂以帮助基因功能鉴定和途径解剖，但是最终的目标是其中一些小分子抑制剂将具有临床应用。在此提案中，我们将建立在赠款第一个周期中启动的分析框架的基础上，但我们还将以多种方式扩大我们的努力。在AIM 1中，我们将在不同的突变体背景下衡量肌球蛋白-II和各种肌动蛋白交联的生命，其中已知力学以评估力学对交联寿命的后果。我们将通过测量分裂突变菌株的皮质力学来测试对细胞因子力学和动力学的分子控制的理解，而我们对机械的特定预测。我们还将通过重新建立交联的肌动蛋白网络，对它们应用机械应变并研究交联链和网络的行为来研究较低的细胞骨架功能较低的分层水平。我们将使用FRAP或单个粒子分析来评估交联寿命的应变依赖性；根据我们的体内研究，我们有几个预测。在AIM 2中，我们将借鉴我们的观察结果，即种族负责在细胞因子过程中产生电阻应力，并限制了我们发现的机械感觉系统。在此目标中，我们将确定种族效应者以充实这一途径。我们将研究14-3-3，该3-3被确定为诺科唑的抑制剂。种族与14-3-3之间的遗传相互作用进一步指向微管调节种族和/或14-3-3的途径，这反过来又调节了全局actacin交叉链接器以控制细胞因子收缩的动力学和力学。在AIM 3中，我们将通过识别已经恢复的Remi突变体中的受影响基因来扩展分子查询。公共卫生相关性：对于正常细胞生长和疾病过程（例如癌症），细胞因子具有非常重要的意义，可以提供丰富的新抗癌药物来源。我们正在努力了解细胞因子如何在基本水平上起作用，以及细胞如何使用蛋白质来产生收缩力的物理特征。最终，有了严格的理解和对过程的完整分子手柄，应该有可能开发出针对特定类型癌细胞特性的更好的癌症疗法。