INTERACTIONS BETWEEN F-ACTIN, MYOSIN II AND MICROTUBULES

F-肌动蛋白、肌球蛋白 II 和微管之间的相互作用

• 批准号: 6387082
• 负责人: GARRETT M ODELL
• 金额: $ 21.44万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2002-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6387082
• 关键词: Caenorhabditis elegans; Drosophilidae; actins; cell cycle; computer program /software; computer simulation; confocal scanning microscopy; intermolecular interaction; mathematical model; microinjections; microtubules; myosins; polymerization

This research aims to figure out mechanistic causes of the 3-D reorganizations of filamentous actin and myosin II that occur in phase with mitotic cycles during pseudo cleavage furrow formation in the syncytial Drosophila blastoderm. Preliminary observations and drug experiments in Drosophila implicate rapidly changing arrays of microtubules as causing periodic reorganization of F-actin and cytoplasmic myosin II (among other biologically important cytoskeletal constituents). Interactions between these key cytoskeletal filaments in cells, if verified and understood, have broad applications in cell biology and in particular in explaining how the contractile ring is positioned to cause cell division. A new combination of embryo fixation techniques and computer-implemented analysis of laser scanning confocal microscope data yields 3-D imaging of the complex cytoskeletal geometry inside large deep cells. These new techniques facilitate high resolution 3-D assessment of perturbations of normal cytoskeletal dynamics caused in Drosophila by maternal effect mutations gnu (giant nuclei), mav (mavericks), and sponge as well as perturbations caused by drug microinjections. These will be analyzed to help verify or reject competing hypotheses about what mechanistic interactions between cytoskeletal elements cause wildtype cytoskeletal kinematics, of which we will generate the definitive 3-D description at closely spaced time points through the mitotic cycle. These new techniques will be extended to make a similar description of wildtype F-actin/myosin II/microtubule dynamics in early blastomeres of C. elegans embryos, discovering to what extent cytoskeletal dynamics in these two study organisms match, and setting the stage for future analysis of mutationally caused perturbations in C. Elegans. A mathematical/computer simulation model will be developed, using a large system of differential equations enforcing the laws of Newtonian mechanics, to compute what cell-level cytoskeletal reorganizations are caused by competing hypotheses about molecular-level interactions between key cytoskeletal constituents. This mathematical model will be used to ascertain whether actin/microtubule and myosin/microtubule molecular-level interactions our experimental analyses imply can actually bring about the cell-level cytoskeletal reorganizations required for early morphogenesis of syncytial Drosophila embryos and cytokinesis in C.elegans blastomeres.

这项研究的目的是找出丝状肌动蛋白和肌球蛋白II的3-D重新组织的机理原因，它们在伪果皮果蝇胚胎中的伪裂解沟形成期间与有丝分裂循环发生。 果蝇中的初步观察结果和药物实验暗示着迅速变化的微管阵列是引起F-肌动蛋白和细胞质肌球蛋白II的定期重组（以及其他重要的细胞骨架成分）。 如果验证和理解细胞中这些关键的细胞骨架丝之间的相互作用在细胞生物学中具有广泛的应用，尤其是在解释收缩环如何定位以导致细胞分裂的位置。 胚胎固定技术和激光扫描共聚焦显微镜数据的新组合，可产生大型深细胞内复杂细胞骨架几何形状的3-D成像。 这些新技术促进了高分辨率的3-D评估，对果蝇正常细胞骨架动力学的扰动评估是由母体效应突变GNU（巨型核），MAV（Mavericks）和海绵以及海绵以及由药物显微注射引起的扰动。 这些将进行分析，以帮助验证或拒绝有关细胞骨架元件之间哪些机械相互作用导致野生型细胞骨架运动学的竞争假设，我们将通过有丝分裂循环在紧密间隔的时间点下生成明确的3-D描述。 这些新技术将扩展，以对秀丽隐杆线虫胚胎早期胚泡中的野生型F-肌动蛋白/肌球蛋白II/微管动力学进行类似的描述，发现这两个研究生物的细胞骨架动力学在多大程度上匹配了何种程度，并为exeleans C. exemans C. exemans c. equastivations的未来分析提供了阶段。 使用强制执行牛顿力学定律的大型微分方程系统，将开发数学/计算机仿真模型，以计算哪些细胞级细胞骨架重组是由竞争的关于分子水平相互作用的钥匙细胞骨架成分之间的分子水平相互作用引起的。 该数学模型将用于确定肌动蛋白/微管和肌球蛋白/微管分子级相互作用是否实验分析是否意味着实际上是否会带来细胞水平的细胞骨架重新组织，以早期对果蝇胚胎胚胎胚胎胚胎和细胞质的静脉内形成型的早期形态发生。