CAREER: Elucidating acentrosomal microtubule organization by integrating cell biology, single molecule imaging and computational modeling

职业：通过整合细胞生物学、单分子成像和计算模型来阐明中心体微管组织

• 批准号: 1453726
• 负责人: Ram Dixit
• 金额: $ 116.39万
• 依托单位: Washington University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-02-01 至 2022-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1453726&HistoricalAwards=false
• 关键词: CAREER; Elucidating; acentrosomal; microtubule; organization

Control of cell shape is a fundamental property of life, essential to the form and function of all organisms. Cell shape is governed primarily by an internal scaffolding structure called the cytoskeleton. Unlike human-made scaffolding structures, the cytoskeleton is highly dynamic and is able to change its configuration in response to developmental and environmental signals, allowing cells to adapt to changing conditions. This project uses the cortical microtubule cytoskeleton of plants as a model to understand how microtubule polymers form highly ordered arrays in the absence of a centralized organizing mechanism. By integrating approaches scaling from single molecules to whole cells, this research will reveal principles by which biochemical activities at the molecular scale result in complex microtubule arrays at the cellular scale, principles expected to be applicable to other such arrays. Since the plant cortical microtubule array directs cell wall assembly, this work might also lead to new strategies to engineer plant biomass for improved food and cellulosic biofuel production. The work from this project will be integrated into education and outreach through inquiry-based activities at multiple levels across the K-20 education spectrum. Specifically, the PI will incorporate this work into a course for Architecture students to inspire new human-made structures based on cellular design principles and a new professional development workshop on Biological Self-Organization to provide high-school teachers with a mathematical biology resource to help them meet the Next Generation Science Standards. He will also integrate work from this project into a problem-based Teen Science Café program, which attracts between 1,000-1,500 students from grades 6-12 annually and is a great opportunity to teach the scientific inquiry process and about dynamic cellular events.The PI will study how noncentrosomal microtubules form highly ordered arrays without the benefit of an organizing center. This problem is fundamentally important because noncentrosomal microtubule arrays are vital for the structure and function of evolutionarily diverse organisms such as fission yeast, humans and plants. To elucidate the underlying mechanisms, the PI will use the cortical microtubule cytoskeleton of Arabidopsis thaliana plants as an experimentally tractable model system. The PI hypothesizes that the net balance of multiple microtubule-associated proteins dynamically controls array structure by regulating the trajectory, length and dynamics of cortical microtubules. To test this hypothesis, a combination of live imaging, in vitro experiments at single molecule resolution and computational modeling will be used to: 1) determine the function of EB1 and associated proteins in regulating the behavior of cortical microtubules, 2) investigate the role of microtubule bundling in array organization, 3) determine how distinct molecular activities interact in space and time to dynamically pattern cortical microtubules, and 4) elucidate the mechanisms that define and change cortical microtubule array orientation in response to developmental and environmental signals. Together, this research will advance our understanding of how distinct cortical microtubule arrays are built to create different cell shapes and how arrays are remodeled in response to signals to modify plant growth. The work from this project will be integrated into multiple education and outreach activities to introduce new biological concepts and techniques into classrooms and to get students interested in pursuing a STEM career. The PI will incorporate this work into a course for Architecture students to inspire new architectural designs based on principles underlying cellular architecture. The PI will also lead a professional development workshop on Biological Self-Organization for high-school teachers, which will combine hands-on activities and computer modeling to provide a mathematical biology resource to take back to classroom. He will also integrate work from this project into a problem-based Teen Science Café program for students from grades 6-12 to teach the scientific inquiry process and about dynamic cellular events.

控制细胞形状是生命的基本特性，对所有组织的形式和功能至关重要。细胞形状由称为细胞骨架的内部脚手架结构来控制。与人造的脚手架结构不同，细胞骨架是高度动态的，并且能够根据发育和环境信号改变其构型，从而使细胞适应不断变化的条件。该项目使用植物的皮质微管细胞骨骼作为模型，以了解在没有集中组织机制的情况下如何形成高度有序阵列的微管聚合物。通过整合从单分子到整个细胞的缩放方法，这项研究将揭示分子尺度生化活性在细胞尺度上导致复杂的微管阵列的原理，预计原理适用于其他此类阵列。由于植物皮质微管阵列指导细胞壁组件，因此这项工作也可能导致新的策略来设计植物生物量以改善食品和纤维素生物燃料的生产。该项目的工作将通过K-20教育范围的多个级别的基于询问的活动纳入教育和外展。具体来说，PI将将这项工作纳入建筑专业的课程中，以激发基于蜂窝设计原理的新人工结构，并进行有关生物自我组织的新专业发展研讨会，以为高中老师提供数学生物学资源，以帮助他们符合下一代科学标准。他还将将该项目的作品整合到一个基于问题的青少年科学咖啡馆计划中，该计划每年吸引1,000-1,500名学生的1,000-1,500名学生，这是一个教授科学询问过程和动态细胞事件的绝佳机会。PI将如何研究非中心微管如何形成高度订购的无订单阵列而没有组织中心的好处。这个问题在根本上很重要，因为非中心微管阵列对于进化生物的结构和功能至关重要，例如裂变酵母，人类和植物。为了阐明潜在机制，PI将使用拟南芥植物的皮质微管细胞骨架作为实验可触及的模型系统。 PI假设多个微管相关蛋白的净平衡通过计算皮质微管的轨迹，长度和动力学来动态控制阵列结构。 To test this hypothesis, a combination of live imaging, in vitro experiments at single molecule resolution and computational modeling will be used to: 1) determine the function of EB1 and associated proteins in reguring the behavior of cortical microtubules, 2) investigate the role of microtubule bundle in array organization, 3) determine how distinct molecular activities interact in space and time to dynamically pattern cortical microtubules, and 4) elucidate the根据发育和环境信号响应的定义和改变皮质微管阵列方向的机制。总之，这项研究将促进我们对如何构建不同皮质微管阵列的理解，以创建不同的细胞形状以及如何根据信号来重塑阵列以修饰植物的生长。该项目的工作将集成到多种教育和外展活动中，以将新的生物学概念和技术引入教室，并使学生有兴趣从事STEM职业。 PI将将这项工作纳入建筑专业的课程中，以基于基于蜂窝架构的原理来激发新的建筑设计。 PI还将为高中老师提供有关生物自我组织的专业发展研讨会，该研讨会将结合动手活动和计算机建模，以提供数学生物学资源，以带回教室。他还将将该项目的作品整合到一个基于问题的青少年科学咖啡馆计划中，旨在为6 - 12年级的学生提供教授科学探究过程和动态蜂窝活动。

项目成果

TANGLED1 mediates microtubule interactions that may promote division plane positioning in maize

• DOI: 10.1083/jcb.201907184
• 发表时间: 2020-08-03
• 期刊: JOURNAL OF CELL BIOLOGY
• 影响因子: 7.8
• 作者: Martinez, Pablo;Dixit, Ram;Rasmussen, Carolyn G.
• 通讯作者: Rasmussen, Carolyn G.

Counting what counts: the importance of quantitative approaches to studying plant cell biology

计算重要的东西：定量方法研究植物细胞生物学的重要性

• DOI: 10.1016/j.pbi.2018.10.003
• 发表时间: 2018
• 期刊: Current Opinion in Plant Biology
• 影响因子: 9.5
• 作者: Haswell, Elizabeth S;Dixit, Ram
• 通讯作者: Dixit, Ram

Mechanism of microtubule plus-end tracking by the plant-specific SPR1 protein and its development as a versatile plus-end marker

• DOI: 10.1074/jbc.ra119.008866
• 发表时间: 2019-11-01
• 期刊: JOURNAL OF BIOLOGICAL CHEMISTRY
• 影响因子: 4.8
• 作者: Balkunde, Rachappa;Foroughi, Layla;Dixit, Ram
• 通讯作者: Dixit, Ram

Quantifying the polymerization dynamics of plant cortical microtubules using kymograph analysis

• DOI: 10.1016/bs.mcb.2020.04.006
• 发表时间: 2020-01-01
• 期刊: PLANT CELL BIOLOGY
• 作者: Zhou, Rudy;Liu, Han;Dixit, Ram
• 通讯作者: Dixit, Ram

Importin-β Directly Regulates the Motor Activity and Turnover of a Kinesin-4

• DOI: 10.1016/j.devcel.2018.01.027
• 发表时间: 2018-03-12
• 期刊: DEVELOPMENTAL CELL
• 影响因子: 11.8
• 作者: Ganguly, Anindya;DeMott, Logan;Dixit, Ram
• 通讯作者: Dixit, Ram