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.

项目概要/摘要： 来自包括酵母和人类在内的所有生物体的隔膜蛋白形成棒状异源寡聚复合物， 被组装成线状细丝和其他更高级的结构，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， 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基因突变导致人类遗传性神经病和不育。Septins也是 与肿瘤发生和神经退行性疾病如阿尔茨海默氏症和帕金森氏症有关。因此，在本发明中， 了解septin的结构和功能不仅对基础科学至关重要， 健康然而，隔膜是如何组装和动态重塑成 各种蜂窝架构以在任何系统中执行不同的功能。 自从最初在芽殖酵母酿酒酵母中发现septins以来，这种生物已经 作为一个非常有效的模型，揭示了septin组装和功能的一般原则。通过 结合酵母遗传学和细胞同步的力量与尖端成像技术 包括铂复型电子显微镜和超分辨光学显微镜，我们已经确定 芽殖酵母中的天然septin结构的构造。隔膜形成一个“早期沙漏”， 分裂位点，由成对的分隔蛋白丝平行于母女轴排列组成。这 后期结构成熟为“带状过渡沙漏”，外带为隔纱网 和肌球蛋白-II纤维在中间区域。过渡沙漏然后被改造成一个“septin双 由周向成对和单丝组成的“环”。双环现在夹着一个 收缩肌动球蛋白环。两种结构共同作用，限制分裂部位的扩散因子 在胞质分裂期间。最近的证据表明，septins也经历了建筑重塑，从一个 从犁沟侵入时的沙漏状结构转变为犁沟侵入时的双环状结构 哺乳动物细胞在这个应用中，我们将：（目的1）确定septin如何高阶组装和稳定性 在酵母胞质分裂之前，分裂位点的LKB 1样激酶控制;（目的2）确定如何 Septin结构重塑在酵母胞质分裂期间由RhoGEF-苯胺醛模块控制;和 (Aim 3）确定隔蛋白在犁沟过程中的结构以及ArhGEF 18和苯胺醛对其的调节 在哺乳动物细胞中的侵入和释放。这项拟议的研究预计将大大推进我们的 对隔蛋白组装、重塑和跨模型系统的功能的机械理解。