Analysis of Septin Structure and Function

Septin结构与功能分析

• 批准号: 10798852
• 负责人: Erfei Bi
• 金额: $ 20.11万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-26 至 2024-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10798852
• 关键词: Actomyosin; Alzheimer' s Disease; Anaphase; Architecture; Bacterial Infections; Basic Science; Biological Models; Cell physiology; Cells; Complex; Cytokinesis; Daughter; Dendritic Spines; Diffusion; Electron Microscopy; Excision; Filament; Genes; Higher Order Chromatin Structure; Human; Imaging technology; Infertility; Malignant Neoplasms; Mammalian Cell; Modeling; Morphogenesis; Mothers; Mutation; Myosin Type II; Neurodegenerative Disorders; Organism; Parkinson Disease; Phosphotransferases; Platinum; Public Health; Regulation; Rod; Role; STK11 gene; Saccharomyces cerevisiae; Saccharomycetales; Shapes; Site; Spermiogenesis; Structure; System; Yeasts; anillin; cell motility; cilium biogenesis; constriction; hereditary neuropathy; light microscopy; overexpression; scaffold; tumorigenesis; ultra high resolution; yeast genetics

Project Summary/Abstract: Septins from all organisms including yeast and humans form rod-shaped heterooligomeric complexes that are assembled into linear filaments and other higher-order structures such as rings and hourglasses. These structures act as a cellular scaffold and/or diffusion barrier to impact diverse cellular functions including cytokinesis, cell migration, ciliogenesis, dendritic spine morphogenesis, spermiogenesis, and bacterial infection. Mutations in septin genes cause hereditary neuropathy and infertility in humans. Septins are also implicated in tumorigenesis and neurodegenerative diseases such as Alzheimer's and Parkinson's. Thus, understanding septin structure and function is critically important not only for basic science but also for public health. However, it remains largely unknown how septins are assembled and dynamically remodeled into various cellular architectures to perform distinct functions in any system. Since the initial discovery of septins in the budding yeast Saccharomyces cerevisiae, this organism has served as a highly effective model for uncovering the general principles of septin assembly and function. By combining the power of yeast genetics and cell synchronization with cutting-edge imaging technologies including platinum-replica electron microscopy and super-resolution light microscopy, we have determined the architectures of the native septin structures in budding yeast. Septins form an “early hourglass” at the division site that consists of paired septin filaments arranged in parallel to the mother-daughter axis. This structure matures into a “zonal transitional hourglass” in anaphase, with a septin gauze at the outer zones and myosin-II filaments in the mid-zone. The transitional hourglass is then remodeled into a “septin double ring” that consists of circumferential paired and single filaments. The double ring now sandwiches a constricting actomyosin ring. Both structures act together to restrict diffusible factors at the division site during cytokinesis. Recent evidence suggests that septins also undergo architectural remodeling from an hourglass-shaped structure during furrow ingression to a double ring-like structure during abscission in mammalian cells. In this application, we will: (Aim 1) determine how septin high-order assembly and stability at the division site is controlled by a LKB1-like kinase before cytokinesis in yeast; (Aim 2) determine how septin architectural remodeling is controlled by a RhoGEF-anillin module during cytokinesis in yeast; and (Aim 3) determine the septin architectures and their regulation by ArhGEF18 and anillin during furrow ingression and abscission in mammalian cells. The proposed study is expected to significantly advance our mechanistic understanding of septin assembly, remodeling, and function across model systems.

项目摘要/摘要： 包括酵母和人类在内的所有生物体的葡聚糖素形成杆状异寡聚体复合体， 组装成线状细丝和其他更高阶的结构，如环和沙漏。这些 结构充当细胞支架和/或扩散屏障，以影响多种细胞功能，包括 胞质分裂、细胞迁移、纤毛发生、树突棘形态发生、精子发生和细菌 感染。Septin基因的突变会导致人类遗传性神经病和不孕症。胡萝卜素也是 与肿瘤发生和阿尔茨海默氏症和帕金森氏症等神经退行性疾病有关。因此， 了解Septin的结构和功能不仅对基础科学而且对公众都是至关重要的 健康。然而，在很大程度上，人们仍然不知道Septins是如何组装并动态重塑成 各种蜂窝架构，可在任何系统中执行不同的功能。 自从在萌芽中的酿酒酵母中首次发现粘附素以来，这种生物已经 为揭示Septin组装和功能的一般原理提供了一个高效的模型。通过 将酵母遗传学和细胞同步化的力量与尖端成像技术相结合 包括铂复制品电子显微镜和超分辨率光学显微镜，我们已经确定 发芽酵母中天然隔膜结构的构筑。毛冬青形成了“早起的沙漏”。 由与母子轴平行排列的成对隔质细丝组成的分裂部位。这 后期结构成熟为“带状过渡性沙漏”，外带有一层隔膜。 中间带有肌球蛋白-II细丝。然后，过渡的沙漏被改装成“双层隔膜”。 环“，由环状的成对细丝和单丝组成。双环现在夹着一个 收缩的肌球蛋白环。这两种结构共同作用，限制了分裂部位的扩散因素 在胞质分裂过程中。最近的证据表明，Septins也经历了来自 沟进时的沙漏状结构到脱落时的双环状结构 哺乳动物细胞。在本应用中，我们将：(目标1)确定Septin如何进行高阶组装和稳定性 在酵母的胞质分裂之前，分裂部位是由LKB1样激酶控制的；(目标2)确定如何 在酵母的胞质分裂过程中，Septin的结构重塑由一个Rhogef-芳香素模块控制； (目的3)确定隔膜蛋白的结构及其在沟槽中受ArhGEF18和苯青素的调节 哺乳动物细胞中的内移和脱落。预计拟议的研究将大大推进我们的 对模型系统中的Septin组装、重塑和功能有机械上的理解。