Cellular Remodeling by Microtubule Severing

通过微管切断进行细胞重塑

• 批准号: 9127286
• 负责人: JENNIFER L ROSS
• 金额: $ 28.55万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE, INC
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9127286
• 关键词: ATP phosphohydrolase; Actins; Animal Model; Basic Science; Biophysical Process; Biophysics; Cardiovascular Diseases; Cell Polarity; Cell division; Cell model; Cell physiology; Cells; Cellular Assay; Centrosome; Clinical; Collaborations; Complex; Cytoskeleton; Data; Development; Disease; Enzymes; Etiology; Excision; Generations; Goals; Health; Human; Human Development; Image Analysis; In Vitro; Injury; Knowledge; Maintenance; Malignant Neoplasms; Mammalian Cell; Mammals; Massachusetts; Medicine; Membrane; Mental Retardation; Methods; Microtubule Proteins; Microtubules; Minus End of the Microtubule; Modeling; Molecular; Morphogenesis; Movement; Names; Normal Cell; Paper; Pathology; Physics; Physiology; Positioning Attribute; Process; Proteins; Published Comment; Publishing; Regulation; Research; Research Proposals; Role; Signal Transduction; Somatic Cell; Testing; Testis; Translating; Tubulin; Universities; Work; Wound Healing; base; biophysical analysis; cell motility; cell type; college; in vivo; insight; katanin; live cell imaging; member; neovascularization; novel; novel therapeutics; polymerization; prevent; professor; programs; reconstitution; repaired; response; single molecule; spastin; tissue regeneration; tissue repair

DESCRIPTION (provided by applicant): Rapid remodeling of the microtubule cytoskeleton is essential for normal cell division, motility and morphogenesis. A unique and intriguing class of proteins involved in this remodeling are the microtubule severing enzymes, so named because of their ability to generate internal breaks in the microtubule lattice, in vitro. The studies outlned in this research proposal will elucidate the cellular functions and biophysical mechanisms of action of members of a still poorly understood subfamily of microtubule severing enzymes, termed fidgetins. The founding member of this subfamily, fidgetin, has long been known to be important for mammalian development, yet the mechanistic basis of its developmental functions remains unclear. In a recent study, we showed that human fidgetin is a microtubule severing enzyme and minus-end depolymerase. We have now found that fidgetin and the closely related protein fidgetin-like 2 perform fundamental but distinct roles in the regulation of human cell migration. Fidgetin localizes to the centrosome and normally promotes cell motility. Cells depleted of fidgetin display severe reduction in motility rates. In stark contrast, fidgetin-like 2 associates with microtubules at the cell edge and normally functions to suppress cell movement. Cells lacking fidgetin-like 2 display a several fold increase in their rate of movement. Moreover, we have found that depletion of fidgetin-like 2 promotes wound healing and neovascularization in animal models. We will pursue the following two specific aims that, together, test the central hypothesis that fidgetin and fidgetin-like 2 recognize and modify distinct microtubule subpopulations thereby controlling different parameters of cell movement: Aim 1: Test the hypothesis that Fidgetin normally promotes cell motility by selectively severing and releasing microtubule minus-ends from centrosomes. Aim 2: Test the hypothesis that Fidgetin-like 2 normally suppresses cell motility by shearing the plus-ends of dynamic microtubules positioned at the cell edge. Our research plan combines complementary state-of-the-art biophysical and cellular approaches to systematically determine 1) how fidgetin and fidgetin-like 2 catalyze the removal of tubulin from the microtubule lattice, 2) how these activities are harnessed in cells to model MT arrays, and 3) how the modeling of cellular MTs by fidgetin or fidgetin-like 2 is translated into altered cell motility. Work will be carried out under the co-direction of David Sharp, an expert cell and molecular biologist, and Jennifer Ross, an expert single molecule biophysicist. Successful completion of the proposed work will provide fundamental insights into the basic mechanisms of microtubule regulation of cell motility, which is a central process in human development and health, and also foundationally establish a body of knowledge for the potential development of novel therapeutic paradigms to enhance tissue regeneration and repair through the manipulation of cell movement.

描述（由申请方提供）：微管细胞骨架的快速重塑对于正常细胞分裂、运动和形态发生至关重要。参与这种重塑的一类独特而有趣的蛋白质是微管切断酶，之所以如此命名是因为它们能够在体外产生微管晶格的内部断裂。在这项研究计划中概述的研究将阐明细胞功能和微管切断酶（称为fidgetins）的一个仍然知之甚少的亚家族成员的生物物理作用机制。这个亚家族的创始成员，fidgetin，长期以来一直被认为是重要的哺乳动物的发育，但其发育功能的机制基础仍然不清楚。在最近的一项研究中，我们发现人fidgetin是一种微管切断酶和负末端解聚酶。我们现在已经发现，fidgetin和密切相关的蛋白质fidgetin-like 2在人类细胞迁移的调节中发挥着基本但不同的作用。Fidgetin定位于中心体，通常促进细胞运动。耗尽fidgetin的细胞显示运动率严重降低。与之形成鲜明对比的是， 与细胞边缘的微管相关，通常起抑制细胞运动的作用。缺乏fidgetin-like 2的细胞显示其运动速率增加数倍。此外，我们已经发现，在动物模型中，fidgetin样2的消耗促进伤口愈合和新血管形成。我们将追求以下两个具体的目标，一起，测试中心的假设，即fidgetin和fidgetin样2识别和修改不同的微管亚群，从而控制不同的参数的细胞运动：目的1：测试的假设，Fidgetin通常促进细胞运动，选择性地切断和释放微管负端从中心体。目标二：测试Fidgetin样2通过剪切位于细胞边缘的动态微管的正端来抑制细胞运动的假设。我们的研究计划结合了互补的最先进的生物物理学和细胞方法，以系统地确定1）fidgetin和fidgetin-like 2如何催化微管蛋白从微管晶格中的去除，2）这些活动如何在细胞中被利用来模拟MT阵列，以及3）fidgetin或fidgetin-like 2对细胞MT的建模如何转化为改变的细胞运动性。这项工作将在细胞和分子生物学家大卫夏普和单分子生物学家詹妮弗罗斯的共同指导下进行。成功完成拟议的工作将提供基本的见解微管调节细胞运动的基本机制，这是人类发育和健康的中心过程，也从根本上建立了一个知识体系，为潜在的开发新的治疗范例，以增强组织再生和修复通过操纵细胞运动。