CAREER: Elucidating the spatiotemporal dynamics of the cyanobacterial circadian clock

职业：阐明蓝藻生物钟的时空动态

• 批准号: 1845953
• 负责人: Susan Cohen
• 金额: $ 73.64万
• 依托单位: California State L A University Auxiliary Services Inc.
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1845953&HistoricalAwards=false
• 关键词: CAREER; Elucidating; spatiotemporal; dynamics; cyanobacterial

We live on a planet that rotates on its axis, creating daily and very predictable changes in our environment; including fluctuations in light intensity, temperature and humidity. In order to cope with these changes many organisms have evolved circadian rhythms, which allow them to coordinate their biological activity over the course of the day. Circadian rhythms, driven by 24-hour biological clocks, are oscillations in biological activity that peak approximately once per day, and are found ubiquitously throughout nature. This project will elucidate how the circadian clock functions in cyanobacteria, which are the simplest organisms and the only bacteria known to possess a robust circadian clock. The aim of this project is to gain a near comprehensive understanding of the cyanobacterial circadian clock, and help set the foundation for leveraging these bacteria for broad ranging applications including bioremediation, biotechnology, and ecological/environmental issues. Additionally the project will provide research training opportunities for students both by providing undergraduate and graduate research assistantships, but will also reach a greater number of students by introducing an element of inquiry-based research into laboratory modules for both introductory and advanced undergraduate courses. These experiences will provide students with hands-on experience in experimental biology, and also the repetitive and progressive development of concepts will allow students to gain a deeper understanding of the material. Moreover, students will present the results of their semester long projects to local elementary and middle school students to promote STEM in K-12 education in the local community. The project aims to investigate how the core oscillator of the cyanobacterium, Synechococcus elongatus PCC 7942, is integrated into a three-dimensional cell and how changes in the spatiotemporal dynamics of the oscillator contribute to the synchronization and robustness of the circadian clock as well as its integration with other cellular processes. While it is known that the subcellular localization and co-localizations of clock proteins that vary in space and time contribute a level of complexity to the circadian clock mechanism, very little is understood about the biological significance of the observed spatiotemporal dynamics occurring with 24-hour periodicity. The research aims to fill in these gaps by investigating how the changes in subcellular localization are achieved and how spatiotemporal changes in the extended clock network contribute to clock function, by using a combination of molecular genetics, biochemistry and cell biology including fluorescence microscopy to determine the subcellular localization of members of the extended clock network and time-lapse imaging to investigate how the inheritance of clock proteins during cell division contributes to the robustness of the circadian clock and the inheritance of timestamps during cell division. A short list of candidates, identified by immunoprecipitation mass-spectrometry analysis, has been identified for possible contributions to promoting changes in the subcellular localization of the core oscillator proteins and preliminary deletion or depletion of these genes results in various circadian defects. None of these candidates have been previously implicated in the circadian mechanism and thus represent novel avenues for understanding how the clock functions in vivo and how the clock is integrated with various cellular processes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

我们生活在一个旋转其轴线的行星上，在环境中创造每天，非常可预测的变化。包括光强度，温度和湿度中的波动。为了应对这些变化，许多生物已经发展出昼夜节律，这使它们可以在一天中协调其生物学活性。由24小时生物钟驱动的昼夜节律是生物学活性的振荡，每天大约峰值一次，并且在整个自然界中都普遍存在。该项目将阐明昼夜节律如何在蓝细菌中起作用，蓝细菌是最简单的生物，也是唯一已知具有强大昼夜节律时钟的细菌。该项目的目的是获得对蓝细菌昼夜节律时钟的近乎全面的了解，并帮助利用这些细菌的基础，用于广泛的应用程序，包括生物修复，生物技术和生态/环境问题。此外，该项目将通过提供本科和研究生研究助理的研究来为学生提供研究培训机会，但也将通过引入有关介绍性和高级本科课程的基于询问的实验室模块研究元素来吸引更多的学生。这些经验将为学生提供实验生物学方面的动手经验，并且概念的重复性和渐进发展将使学生能够更深入地了解材料。此外，学生将向当地的小学和中学生介绍他们的学期长期项目的结果，以促进当地社区的K-12教育中的STEM。该项目旨在调查蓝细菌的核心振荡器Synechococcus Elongatus PCC 7942如何集成到三维细胞中，以及振荡器时空动力学的变化如何有助于昼夜节律时钟的同步和稳健性和其他细胞过程的稳健性。众所周知，在时空上和时间和时间上有不同的时钟蛋白的亚细胞定位和共定位，这对昼夜节律时钟机制造成了一定的复杂程度，但几乎没有理解观察到的时空动力学的生物学意义，而存在于24 h时期。该研究的目的是通过研究如何实现亚细胞定位的变化以及如何通过使用分子遗传学，生物化学和细胞生物学的组合来填补亚细胞定位的变化，以及如何在延长时钟网络中的时空变化对时钟功能有所影响昼夜节律时钟的稳健性和在细胞分裂过程中时间戳的继承。通过免疫沉淀质谱分析确定的候选人的简短清单已被鉴定出来，以促进核心振荡蛋白的亚细胞定位变化以及这些基因的初步缺失或耗竭导致各种昼夜节律缺陷。这些候选者以前都没有与昼夜节律机制有关，因此代表了理解时钟如何在体内发挥作用的新途径，以及如何与各种蜂窝过程集成到时钟。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的智力和更广泛影响的评估来通过评估来获得支持的值得的。