Mechanistic Analysis of Cytokinesis in Eukaryotes

真核生物细胞分裂的机制分析

• 批准号: 9316658
• 负责人: Erfei Bi
• 金额: $ 42.56万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9316658
• 关键词: Actomyosin; Address; Anemia; Aneuploidy; Animals; Architecture; Biological Assay; Biology; C2 Domain; CRISPR/Cas technology; Cell Count; Cells; Chitin Synthase; Complex; Cytokinesis; Data; Defect; Development; Disease; Elements; Enzymes; Eukaryota; Evolution; Experimental Models; Extracellular Matrix; Failure; Filament; Genomic Instability; Homeostasis; In Vitro; Liposomes; Malignant Neoplasms; Mammalian Cell; Mediating; Membrane; Membrane Fusion; Microfilaments; Microscopy; Modeling; Myosin ATPase; Neck; Neurons; Organism; Platinum; Play; Ploidies; Prevalence; Process; Protein Isoforms; Proteins; Regulation; Research; Resolution; Role; Saccharomyces cerevisiae; Saccharomycetales; Sarcomeres; Site; Structure; System; Technology; Testing; Tissues; Transglutaminases; Vesicle; Yeasts; base; cell type; constriction; design; genome editing; human disease; in vivo; innovation; innovative technologies; novel; phenomenological models; public health relevance; scaffold; spatiotemporal; success

 DESCRIPTION (provided by applicant): Cytokinesis is essential for development and survival of all organisms. Defects in cytokinesis cause aneuploidy and genomic instability, and thereby contribute to serious diseases such as cancer, neuronal disorders, and anemia. Thus, mechanistic study of cytokinesis is important not only for understanding the basic principles of a fundamental process but also for designing new strategies to treat human diseases. Cytokinesis in animal and fungal cells requires concerted functions of a contractile actomyosin ring (AMR), targeted vesicle fusion, and localized extracellular matrix (ECM) remodeling. Despite extensive studies of cytokinesis over a century, the basic architecture of the AMR remains unknown in any system. It is also unclear how myosin-II localization and filament assembly are regulated during cytokinesis. Increasing evidence suggests that ECM remodeling is critical for cytokinesis not only for yeast cells but also for animal cells. However, the underlying mechanisms remain poorly understood. We propose to address these key questions in cytokinesis using both budding yeast and mammalian cells as our experimental models. In Aim 1, we will determine the AMR structure in budding yeast and then develop a quantitative model for it. This model will open new avenues to address broad questions in cytokinesis, e.g. those regarding the mechanism of ring constriction as well as those concerning the assembly, regulation, and function of the ring. We will also examine the AMR in mammalian cells to establish the degree of conservation in this core cytokinetic structure. In Aim 2, we will test our hypothesis that IQGAP functions as a dual regulator of myosin localization and filament assembly during cytokinesis in both budding yeast and mammalian cells. In Aim 3, we will test our hypothesis that the AMR-associated protein Inn1 interacts with SNAREs via its C2 domain to facilitate vesicle fusion at the division site, thereby increasing the local concentration of the cargo enzyme Chs2 (chitin synthase-II), which is subsequently activated by Cyk3 via its transglutaminase-like domain to promote septum formation (equivalent of ECM remodeling in animal cells) during cytokinesis. The proposed research is innovative, as diverse and cutting-edge technologies will be applied to generate new information and concepts regarding the core mechanisms of cytokinesis.

 描述（由申请人提供）：细胞分裂对于所有生物体的发育和生存至关重要。胞质分裂缺陷会导致非整倍性和基因组不稳定，从而导致癌症、神经元疾病和贫血等严重疾病。因此，胞质分裂的机制研究不仅对于理解基本过程的基本原理很重要，而且对于设计治疗人类疾病的新策略也很重要。动物和真菌细胞中的细胞分裂需要收缩肌动球蛋白环 (AMR)、靶向囊泡融合和局部细胞外基质 (ECM) 重塑的协同功能。尽管一个多世纪以来对胞质分裂进行了广泛的研究，但 AMR 的基本结构在任何系统中仍然未知。目前还不清楚肌球蛋白-II 定位和丝组装在胞质分裂过程中是如何调节的。越来越多的证据表明，ECM 重塑对于酵母细胞和动物细胞的胞质分裂至关重要。然而，其根本机制仍知之甚少。我们建议使用芽殖酵母和哺乳动物细胞作为我们的实验模型来解决胞质分裂中的这些关键问题。在目标 1 中，我们将确定芽殖酵母中的 AMR 结构，然后为其开发定量模型。该模型将为解决胞质分裂中的广泛问题开辟新途径，例如关于环收缩机制的那些以及关于环的组装、调节和功能的那些。我们还将检查哺乳动物细胞中的 AMR，以确定该核心细胞因子结构的保守程度。在目标 2 中，我们将检验我们的假设，即 IQGAP 在芽殖酵母和哺乳动物细胞的胞质分裂过程中充当肌球蛋白定位和丝组装的双重调节器。在目标 3 中，我们将测试我们的假设，即 AMR 相关蛋白 Inn1 通过其 C2 结构域与 SNARE 相互作用，以促进分裂位点的囊泡融合，从而增加货物酶 Chs2（几丁质合酶-II）的局部浓度，随后 Cyk3 通过其转谷氨酰胺酶样结构域激活该酶，以促进隔膜形成（相当于 ECM） 动物细胞的重塑）在胞质分裂期间。拟议的研究具有创新性，因为将应用多样化的尖端技术来产生有关胞质分裂核心机制的新信息和概念。