Uncovering how the dynamic architecture of a layered contractile ring induces furrow ingression

揭示分层收缩环的动态结构如何引起沟槽侵入

• 批准号: 10224713
• 负责人: Caroline Laplante
• 金额: $ 30.7万
• 依托单位: NORTH CAROLINA STATE UNIVERSITY RALEIGH
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10224713
• 关键词: Abnormal Cell; Actin-Binding Protein; Actins; Actomyosin; Address; Affect; Alleles; Animal Model; Architecture; Biological Models; Biology; Bundling; Cell division; Cell membrane; Cells; Complex; Congenital Abnormality; Contractile Proteins; Cytokinesis; Cytoplasm; Data; Defect; Development; Disease; Event; Fission Yeast; Fluorescence; Foundations; Generations; Genes; Genetic Materials; Human; Immune System Diseases; Individual; Kinetics; Knowledge; Lasers; Lead; Life; Light; Malignant Neoplasms; Measures; Mechanics; Membrane; Methodology; Microfilaments; Microscopy; Microsurgery; Modeling; Molecular; Mothers; Motor; Mutation; Myosin ATPase; Organism; Outcome; Pathogenesis; Plus End of the Actin Filament; Process; Production; Proteins; Publishing; Research; Research Proposals; Role; Speed; Structure; System; Testing; Work; Yeasts; base; cell cortex; confocal imaging; constriction; daughter cell; frontier; fungus; imaging genetics; innovation; molecular dynamics; nanometer resolution; nervous system disorder; novel; photoactivation; public health relevance; transmission process

Project description: 30 lines Cytokinesis, the separation of a mother cell into two daughter cells, is one of life's most fundamental processes; it is central to the making of multicellular organisms and the transmission of genetic material across generations. The core machinery of cytokinesis is a contractile ring of actin, myosin motors and other proteins and is conserved from fungi to human. The contractile ring is connected to the inside of the cell cortex and its constriction leads the ingression of the plasma membrane into a furrow between the two cytoplasmic compartments that will become individual cells after the completion of cell division. Furrow ingression requires the cooperation between two main mechanisms: 1) constriction of actin filaments by the action of myosin motors and 2) the transmission of this contractile force to the plasma membrane via anchor proteins that connect the actomyosin bundle to the plasma membrane. We found that the proteins of the contractile ring occupy distinct layers with plasma membrane-interacting proteins in the outer layer adjacent to the cortex and the force- producing myosin motors in the inner layer. The next frontier in understanding the mechanism of cytokinesis is to determine how these proteins are organized into complex structures, how these structures move within the contractile ring and are removed from the ring during constriction, and how this dynamic architecture governs the force-generation function of the contractile rings. The objective of this application is to determine the anchoring role of the outer ring and the tension-force producing role of the inner ring by uncovering their dynamic architecture and effects on mechanics of constriction. Our hypothesis is that furrow ingression results from contractile forces produced in the inner layer of the contractile ring, conveyed to the plasma membrane via anchoring achieved by proteins in the outer layer. We plan to test our central hypothesis with the following Specific Aims: 1) determine how cytokinetic node proteins anchor the contractile ring and transmit contractile forces to the plasma membrane during furrow ingression and 2) determine how the molecular architecture of the inner ring governs the constriction of the contractile ring during furrow ingression. The proposed research in this application is innovative because we will use a unique combination of high-speed Fluorescence Photoactivation Localization Microscopy (hsFPALM) in live cells to determine protein organization and its dynamics with laser microsurgery to probe the mechanics of this tension-force producing machine in live cells. The proposed research in this application is significant as it will result in the identification of previously unknown parameters for new molecular and functional models of the contractile ring. As the proteins of the contractile ring are conserved from yeast to human, we expect that the core mechanism of cytokinesis elucidated in fission yeast will act as a template for understanding the mechanism of cytokinesis and even perhaps other non-musclecontractile cellular machines in other species.

项目描述：30行 细胞因子是母细胞分为两个子细胞的细胞因子，是生命中最基本的过程之一。 它是多细胞生物和遗传物质在各个一代的传播至关重要的。 细胞因子的核心机械是肌动蛋白，肌球蛋白电机和其他蛋白质的收缩环，是 从真菌到人保守。收缩环连接到细胞皮质的内部及其内部 收缩导致质膜进入两个细胞质之间的沟 细胞分裂完成后将成为单个细胞的隔室。犁沟的入口需要 两种主要机制之间的合作：1）肌动蛋白电动机的作用收缩肌动蛋白丝 2）通过连接的锚蛋白将这种收缩力传输到质膜 肌动蛋白束至质膜。我们发现收缩环的蛋白质占据了独特的 在与皮质相邻的外层中具有质膜相互作用蛋白的层和力 在内层产生肌球蛋白电机。了解细胞因子机理的下一个领域是 为了确定这些蛋白质如何组织成复杂的结构，这些结构如何在内部移动 收缩环，并在收缩期间从环上删除，以及这种动态体系结构如何控制 收缩环的力产生功能。此应用的目的是确定 外环的锚定作用和张力强度通过揭示其动态而产生内环的作用 建筑和对收缩力学的影响。我们的假设是，沟的吸入是由 收缩力在收缩环内层产生的收缩力，通过 由蛋白质在外层中实现的锚定。我们计划通过以下来检验我们的中心假设 具体目的：1）确定细胞力学节点蛋白如何锚定收缩环和发射收缩 在犁沟入口期间向质膜的力和2）确定分子结构如何 内环控制着犁沟入口期间收缩环的收缩。拟议的研究 应用是创新的，因为我们将使用高速荧光光活化的独特组合 活细胞中的定位显微镜（HSFPALM）确定蛋白质组织及其动力学用激光确定 显微外科手术，以探测活细胞中这种张力力生产机器的力学。提议 该应用程序中的研究很重要，因为它将导致鉴定以前未知参数 收缩环的新分子和功能模型。由于收缩环的蛋白质是保守的 从酵母到人，我们期望在裂变酵母中阐明的细胞因子的核心机制将充当 了解细胞因子的机理，甚至可能其他非肌肉收缩细胞的机制 其他物种中的机器。