CAREER: The Regulation of Cytokinesis by Calcium

职业：钙对细胞分裂的调节

• 批准号: 2144701
• 负责人: Qian Chen
• 金额: $ 70.09万
• 依托单位: University of Toledo
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2144701&HistoricalAwards=false
• 关键词: CAREER; Regulation; Cytokinesis; Calcium

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117- 2).Millions of rounds of cell division are required for an embryo to become a fully developed human. How a cell can divide so reliably with precise timing and spatial cues is a fundamental biological question. One enduring mystery about cell division remains the involvement of calcium. We have long known that two quick currents consisting of calcium ions run through an embryonic cell during the last step of cell division called cytokinesis. These transient currents could potentially serve as the triggering signal, like a light switch, for the separation of two replicated daughter cells. However, their origin and function remain poorly understood due to technological challenges. This project will tackle this question by taking advantage of two fairly recent breakthroughs. The first is the conceptual advance of employing the simple fission yeast to study cytokinesis. This yeast is easy to manipulate genetically, but its cytokinesis is similar to that of the animal cells. The second is the technical advance of quantitative microscopy that can measure calcium current in live cells with high precision. The project will take advantage of these advances to uncover how calcium works during cytokinesis. Broader Impact activities include the intrinsic merit of the research as all eukaryotic cells likely utilize calcium signals during division. Additional activities involve the training of high school, undergraduate, and graduate students in research. The PI will extend the experience for high school students with remote controlled microscopes during the school year and he will also engage in activities to prepare and attract economically disadvantaged students for college. American Rescue Plan funding provides support for the investigator at a critical stage in his career.In this project, investigators will build on early advances to determine the mechanism of the calcium spikes. 1) The investigators will determine how the calcium spike arises in dividing fission yeast cells. We will test whether a special type of ion channels called mechanosensitive channels initiate the calcium spike. Then they will test whether two calcium pumps Pmr1 and Pmc1 clear out the excessive calcium so that the spikes are transient. 2) The investigators will determine how the calcium spike regulates the force-generator of cytokinesis the contractile ring. They will test whether the calcium spike promotes the activity of calcium-sensitive molecule Ppb1 which then proceeds to activate the motor protein type II myosins in the ring. They will measure how Ppb1 is recruited and activated in the ring and determine the activity and number of myosins in the mutant cells without Ppb1. This will be followed by the experiment to determine whether the myosin regulatory light chain is a substrate of Ppb1. 3) The investigators will determine how the calcium spike regulates the last step of cytokinesis the cell separation. They will determine whether the spike helps build the cell wall for yeast cells and maintain the integrity of the membrane through the activity of the calcium-sensitive molecule Cam1. They will employ yeast genetics, calcium imaging, atomic force microscopy and quantitative microscopy in the project. The investigators expect it will finally address the long-standing questions, where these cytokinetic calcium currents come from and what are their functions.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.

该奖项是根据2021年《美国救援计划法》（第117-2）的全部或部分资助的。胚胎成为一个完全发达的人，需要数百万的细胞分裂。细胞如何通过精确的时机和空间提示如此可靠地分裂是一个基本的生物学问题。关于细胞分裂的一个持久谜团仍然是钙的参与。我们早就知道，在细胞分裂的最后一步中，由钙离子通过胚胎细胞的两种快速电流称为细胞因子。这些瞬态电流可能有可能用作触发信号，例如光开关，以分离两个复制的子细胞。但是，由于技术挑战，它们的起源和功能仍然很糟糕。该项目将通过利用两个相当最近的突破来解决这个问题。首先是使用简单的裂变酵母研究细胞因子的概念进步。该酵母很容易在遗传上操纵，但其细胞因子与动物细胞相似。第二个是定量显微镜的技术进步，可以测量具有高精度的活细胞中的钙电流。该项目将利用这些进步来揭示钙在细胞因子过程中的工作原理。 更广泛的影响活性包括研究的内在优点，因为所有真核细胞可能在分裂过程中使用钙信号。 其他活动涉及研究高中，本科生和研究生的培训。 PI将在学年期间为具有遥控显微镜的高中学生提供体验，他还将从事活动，以准备和吸引经济不利的学生上大学。 美国救援计划的资金在其职业生涯的关键阶段为调查员提供了支持。在该项目中，调查人员将基于早期进步来确定钙尖峰的机制。 1）研究人员将确定钙尖峰如何在分裂裂变酵母细胞中产生。我们将测试一种称为机械敏感通道的特殊类型的离子通道启动钙尖峰。然后，他们将测试两个钙泵PMR1和PMC1是否清除过多的钙，使得峰值是短暂的。 2）研究人员将确定钙尖峰如何调节收缩环细胞因子的力生成剂。他们将测试钙尖峰是否促进钙敏感分子PPB1的活性，然后继续激活环中的运动蛋白II型肌动物。他们将测量如何在环中募集和激活PPB1，并确定没有PPB1的突变细胞中肌球蛋白的活性和数量。随后将进行实验，以确定肌球蛋白调节轻链是否是PPB1的底物。 3）研究人员将确定钙尖峰如何调节细胞分离的最后一步。他们将确定尖峰是否有助于通过钙敏感分子CAM1的活性来建造酵母细胞的细胞壁并维持膜的完整性。他们将在项目中采用酵母遗传学，钙成像，原子力显微镜和定量显微镜。调查人员希望最终解决这些长期存在的问题，这些细胞动力学的钙电流来自何处以及它们的功能是什么。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知识分子和更广泛的影响评论来通过评估来支持的。标准。

项目成果

Membrane stretching activates calcium permeability of a putative channel Pkd2 during fission yeast cytokinesis.

• DOI: 10.1091/mbc.e22-07-0248
• 发表时间: 2022-12-01
• 期刊: MOLECULAR BIOLOGY OF THE CELL
• 影响因子: 3.3
• 作者: Poddar, Abhishek;Hsu, Yen-Yu;Zhang, Faith;Shamma, Abeda;Kreais, Zachary;Muller, Clare;Malla, Mamata;Ray, Aniruddha;Liu, Allen P.;Chen, Qian
• 通讯作者: Chen, Qian

The cytoplasmic tail of the mechanosensitive channel Pkd2 regulates its internalization and clustering in eisosomes

机械敏感通道 Pkd2 的胞质尾部调节其在 eisosomes 中的内化和聚集

• DOI: 10.1242/260598
• 发表时间: 2023
• 期刊: Journal of Cell Science
• 影响因子: 4
• 作者: Malla, Mamata;Sinha, Debatrayee;Chowdhury, Pritha;Bisesi, Benjamin Thomas;Chen, Qian
• 通讯作者: Chen, Qian