Molecular mechanisms of cell shape change in cytokinesis

胞质分裂过程中细胞形态变化的分子机制

• 批准号: 9132813
• 负责人: Amy Shaub Maddox
• 金额: $ 36.74万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-21 至 2017-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9132813
• 关键词: Accounting; Actins; Actomyosin; Adverse effects; Aneuploidy; Animal Model; Antineoplastic Agents; Apoptosis; Behavior; Biological Assay; Biological Models; Biomechanics; Biophysical Process; Bundling; Caenorhabditis elegans; Cell Cycle Proteins; Cell Shape; Cell division; Cell membrane; Cells; Chimeric Proteins; Clinic; Collaborations; Complex; Computer Simulation; Coupled; Cytokinesis; Cytoskeletal Filaments; Cytoskeleton; Data; Development; Drug Targeting; Event; F-Actin; Failure; Feedback; Filament; Gastrointestinal tract structure; Geometry; Goals; Human body; Image Analysis; Interphase Cell; Kinetics; Laboratories; Life; Malignant Neoplasms; Mammals; Measures; Mechanics; Membrane; Methods; Mitotic; Modeling; Molecular; Mothers; Myosin ATPase; Nature; Organelles; Pathology; Persons; Pharmaceutical Preparations; Phylogeny; Positioning Attribute; Process; Proteins; Regulation; Role; Shapes; Skin; Slide; Structural Genes; Tetraploidy; Time; Tissues; Uncertainty; United States National Institutes of Health; Work; base; cancer cell; constriction; daughter cell; innovation; insight; interdisciplinary approach; microscopic imaging; novel; protein function; quantitative imaging; single molecule; success; tumor; zygote

Cytokinesis, the physical division of one cell into two, is accomplished by a transient organelle called the contractile ring. The PI is focused on the molecular and biophysical mechanisms of contractile ring function. Ongoing work in the PI's laboratory has yielded an explanation of asymmetric (non-concentric) ring closure, which is seen throughout metazoa. To explain this asymmetry, a biomechanical feedback loop was proposed, among cytoskeletal filament alignment, filament sliding, and membrane curvature. An in silico model based on this feedback can recapitulate ring closure asymmetry, as well as the kinetics of closure initiation and duration in the C. elegans zygote, the primary animal model for this work. To expand and strengthen this model, the proposed work aims to define the molecular and physical mechanisms of each component of the feedback loop. Specifically, the conserved proteins that contribute to alignment of cytoskeletal filaments with each other and with the membrane will be defined. The existence of myosin in the form of bipolar minifilaments in the contractile ring will be defined. Last, the shape of the cell throughout cytokinesis will be described and correlated with local protein enrichment and organization. The proposal centers on the use of three dimensional live-cell (time-lapse) microscopy and quantitative image analysis. Several novel quantitative assays for contractile ring assembly, organization and function will be used. These include ways to measure F-actin alignment, kinetics and position of ring closure throughout cytokinesis, the number of molecules in macromolecular cortical complexes, and the three-dimensional shape of the cell during the course of division. The C. elegans zygote serves as an ideal model system for these studies due to its reproducible size, shape, and the kinetics of cell division events, the ease of thorough depletion of essential proteins, the ability to examine the first cell division attempted following protein depletion, and the availability of strains stably expressing fluorescent fusion proteins that serve as markers for various subcellular components and compartments. Importantly, cell cycle regulatory and structural proteins are conserved among C. elegans and mammals. The long-term goal of this work is to aid the development of anti-cancer chemotherapeutics that block cytokinesis. Targeting proteins that act specifically in the contractile ring should avoid the side effects on non-dividing cells of many popular drugs. In addition, because currently used anti-mitotics also have limited success against some tumor types, development of cytokinesis drugs will be a welcome expansion and diversification of our arsenal against cancers.

胞质分裂，即一个细胞分裂为两个细胞的过程，是通过一个短暂的 一种叫做收缩环的细胞器PI专注于分子和生物物理 收缩环功能的机制。PI实验室正在进行的工作已经产生了一个 不对称（非同心）环闭合的解释，这是整个后生动物。到 为了解释这种不对称性，提出了细胞骨架之间的生物力学反馈回路， 细丝排列、细丝滑动和膜弯曲。基于此的计算机模型 反馈可以概括环闭合的不对称性，以及闭合启动的动力学 和持续时间。elegans受精卵，这项工作的主要动物模型。 为了扩展和加强这一模型，拟议的工作旨在定义分子和 反馈回路的每个组件的物理机制。特别是，保守的 这些蛋白质有助于细胞骨架丝彼此之间以及与细胞骨架丝之间的对齐。 膜将被定义。肌球蛋白以双极微丝的形式存在于肌纤维中， 将定义收缩环。最后，整个胞质分裂过程中细胞的形状将是 描述并与局部蛋白质富集和组织相关。 该提案的核心是使用三维活细胞（延时）显微镜， 定量图像分析几种新的收缩环组装的定量测定， 组织和功能将被使用。这些方法包括测量F-肌动蛋白排列的方法， 在整个胞质分裂中，环闭合的动力学和位置， 大分子皮质复合物，以及细胞在生长过程中的三维形状。 分裂的过程。梭线虫受精卵是这些研究的理想模型系统 由于其可再现的大小、形状和细胞分裂事件的动力学， 消耗必需蛋白质，检查第一次细胞分裂的能力尝试以下 蛋白质消耗，以及稳定表达荧光融合蛋白的菌株的可用性， 用作各种亚细胞组分和区室的标记。重要的是，细胞周期 调节和结构蛋白在C.和哺乳动物。 这项工作的长期目标是帮助抗癌化疗药物的发展 阻止胞质分裂针对收缩环中特异性作用的蛋白质应避免 许多常用药物对非分裂细胞的副作用。此外，由于目前使用 抗有丝分裂剂对某些肿瘤类型的成功也有限， 药物将是我们抗癌武器库的一个值得欢迎的扩展和多样化。