The Mechanics of Actin-mediated Cell Protrusion

肌动蛋白介导的细胞突出的机制

• 批准号: 7924275
• 负责人: Gaudenz Danuser
• 金额: $ 12.56万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-15 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7924275
• 关键词: Abbreviations; Actins; Actomyosin; Adhesions; Binding; Biological; Cell membrane; Cells; Chemicals; Classification; Color; Coupled; Data; Development; Dissociation; Epithelial Cells; Equilibrium; F-Actin; Family member; Feedback; Figs - dietary; Filament; G Actin; Generations; Goals; Growth; Growth Factor; Image; In Situ; Joints; Kinetics; Life; Link; Measurement; Measures; Mechanics; Mediating; Methodology; Methods; Microfilaments; Microscopy; Minor; Modeling; Names; Neoplasm Metastasis; Nonlinear Dynamics; Organelles; Pathway interactions; Principal Investigator; Process; Proteins; Quantitative Microscopy; Relative (related person); Research; Resolution; Science; Side; Signal Transduction; System; Testing; Time; Tropomyosin; Work; acronyms; base; cell motility; cofilin; cofilin 2; depolymerization; network models; neuronal cell body; novel; p21 activated kinase; polymerization; programs; protein complex; research study; response; rho GTP-Binding Proteins

DESCRIPTION (provided by applicant): Protrusion of the leading edge is the first step in directed cell migration, a critical process in both cancer metastasis and normal development. It requires polymerization of actin filaments (F-actin) at the leading edge plasma membrane in exquisite balance with both network adhesion and contraction, all under the control of regulatory signals. The long term goal of my research program is to create systems-level models of the integration of these mechanical and chemical pathways as a non-steady state and spatially distributed process. The project proposed here is based on our discovery of two dynamically, molecularly, and functionally distinct but spatially overlapping F-actin networks, named lamella (La) and lamellipodium (Lp) (Ponti et al, Science 2004). The central hypothesis of this proposal suggests that cell protrusion is driven by elongation of actin filaments in the contractile La network which engages with adhesions and spans the region between the cell body and the leading edge. The Lp is a narrow, fast treadmilling F-actin network that assembles off of La-filaments via Arp2/3 and cofilin activity. However, according to our hypothesis the Lp only makes minor contributions to the generation of propulsive forces itself, but rather modulates the dynamics of La filament assembly. Thus, our model defines the Lp as a regulatory organelle of cell protrusion. To test this prediction we will integrate quantitative high-resolution live cell microcopy and image data driven modeling approaches to achieve three Specific Aims: 1.) Test the hypothesis that Lp F-actin assembles off elongating La filaments and transiently dissociates under the competing activities of tropomyosin and cofilin; 2.) Test the hypothesis that La F-actin assembly is coupled to La network contraction via RhoA signals. 3.) Test the hypothesis that Lp dynamics modulate La-mediated cell protrusion in both EGF-stimulated and random cell migration. The cell biological deliverable of this project is the deconvolution of several mechanochemical pathways by systematic in situ analysis of their modes of action and timing during cell protrusion. The technological deliverables will be a unique and robust methodology to probe the dynamic interaction of two protein assemblies and their relationship to intracellular forces in live cell analyses. Second, the non-steady state measurements provided by these methods will initiate novel numerical modelling to recapitulate the non-linear dynamics of cell protrusion.

描述（由申请人提供）：前缘的突出是定向细胞迁移的第一步，这是癌症转移和正常发育的关键过程。它需要在调节信号的控制下以精致的平衡和网络粘附和收缩，在前沿质膜上聚合肌动蛋白丝（F-肌动蛋白）。我的研究计划的长期目标是创建系统级模型，以将这些机械和化学途径作为非稳态和空间分布的过程集成。这里提出的项目基于我们在动态，分子和功能上不同但在空间上重叠的F-肌动蛋白网络的发现，称为Lamella（La）和Lamellipodium（LP）（Ponti等，Science 2004）。该提案的中心假设表明，细胞突出是由收缩LA网络中肌动蛋白丝的伸长驱动的，该网络与粘附并跨越细胞体和前缘之间的区域。 LP是一个狭窄，快速的跑步机F-肌动蛋白网络，通过ARP2/3和Cofilin活性从LA丝中组装。但是，根据我们的假设，LP仅对推进力本身的产生做出了较小的贡献，而是调节了La细丝组装的动力学。因此，我们的模型将LP定义为细胞突出的调节细胞器。为了测试这一预测，我们将整合定量高分辨率的活细胞微拷贝和图像数据驱动的建模方法，以实现三个特定目的：1。）检验以下假设：LP F-肌动蛋白在延长LA细丝的情况下会组装出la丝和在肌黄素和富甲素的竞争活性下瞬时分离； 2.）检验以下假设：LA F-肌动蛋白组装通过RhoA信号耦合到LA网络收缩。 3.）测试LP动力学在EGF刺激和随机细胞迁移中调节LA介导的细胞突出的假设。该项目的细胞生物学可交付是通过系统地分析细胞突起期间的作用模式和时间安排的几种机械化学途径的反卷积。该技术可交付成果将是一种独特而强大的方法，用于探测两个蛋白质组件的动态相互作用及其与细胞内力的关系。其次，这些方法提供的非稳态测量结果将启动新型的数值建模，以概括细胞突出的非线性动力学。