Evolutionary adaptation and spatial organization of signaling in the Mitotic Exit Network

有丝分裂出口网络中信号的进化适应和空间组织

• 批准号: 10331332
• 负责人: Xiaoxue Zhou
• 金额: $ 10万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10331332
• 关键词: Address; Anaphase; Binding; Binding Sites; Biological Models; Case Study; Cell Cycle Progression; Cell Cycle Regulation; Cell Nucleolus; Cell division; Cell membrane; Cell physiology; Cells; Centrosome; Complex; Development; Dimerization; Disease; Ensure; Eukaryota; Evolution; Foundations; Functional disorder; Future; Guanosine Triphosphate Phosphohydrolases; Homologous Gene; Human; Hybrids; Knock-out; Label; Life; Light; Location; Logic; Malignant Neoplasms; Mammalian Cell; Mammals; Mediating; Meiosis; Mentors; Mitochondria; Mitogen-Activated Protein Kinases; Mitosis; Mitotic; Modeling; Nucleotides; Organism; Pathway interactions; Phase; Phosphoric Monoester Hydrolases; Phosphotransferases; Positioning Attribute; Process; Protein phosphatase; Proteins; Quantitative Microscopy; Regulation; Research; Research Personnel; Saccharomycetales; Signal Pathway; Signal Transduction; Surface; System; Testing; Training; Work; Yeasts; base; career; comparative; experimental study; information processing; inhibitor; insight; mutant; optogenetics; pressure; prevent; scaffold; spindle pole body; tool

Project Summary Sensing and processing information through signaling cascades is an essential part of cellular life. A few signaling cascades such as the MAP kinase and Hippo pathways are ubiquitous among eukaryotes yet perform different functions across organisms. Although these pathways are well-studied, how they evolve to take on new functions and adapt to new inputs remains poorly understood. The Mitotic Exit Network (MEN), a Ras-like GTPase signaling cascade and yeast homolog of the Hippo pathway, provides a unique opportunity to study this question. In the MEN, the same core signaling components operate in distinct manners under different developmental trajectories. During yeast mitosis which occurs through an asymmetric cell division called budding, the MEN is scaffolded onto the spindle pole bodies (SPB, the yeast equivalent of centrosomes) and responds to spindle position through its GTPase Tem1. During meiosis, where budding is suppressed and thus no need to sense spindle position, MEN signaling is no longer organized at the SPBs, and it is unclear whether Tem1 is still required for MEN activation and what signal it may respond to. To understand the adaptation of the MEN under distinct cellular contexts, this proposal will test the hypothesis that this adaptation is enabled partially by different activation mechanisms of the MEN kinase Cdc15, the effector kinase of Tem1, between mitosis and meiosis (Aim 1). In contrast to the drastic change in spatial organization of the MEN core components between mitosis and meiosis, the effector protein of the MEN, the phosphatase Cdc14, remains sequestered in the nucleolus prior to activation both in mitosis and meiosis. In fact, this nucleolar localization of Cdc14 is conserved from yeast to human. Sequestration of Cdc14 in the nucleolus could function either 1) to ensure tight inhibition of Cdc14’s phosphatase activity prior to activation or 2) to localize Cdc14 to dephosphorylate specific substrates in the nucleolus. To uncover the selection pressure that maintains this conserved nucleolar localization of Cdc14, this proposal will examine these two hypotheses by sequestering Cdc14 elsewhere in the cell and characterize the consequences first in yeast and then in mammalian cells (Aim 2). The experiments within both aims will be initiated during the K99 phase which also includes training of the candidate on new experimental systems such as yeast meiosis and mammalian cells, as well as the development and implementation of quantitative microscopy, proximity labeling and optogenetics. Furthermore, the candidate has assembled an outstanding mentor team to both advise her scientifically to facilitate progress of the project and prepare her for the transition to an independent investigator. Together, this proposal will create a strong foundation for an independent research career in understanding the evolution/adaptation and spatial organization of cellular signaling.

项目摘要 通过信号级联向传感和处理信息是细胞寿命的重要组成部分。几个 诸如MAP激酶和河马途径之类的信号传导级联反应在真核生物中无处不在 在各种生物体之间执行不同的功能。尽管这些途径是经过充分研究的，但它们如何发展为 采取新功能并适应新的投入仍然知之甚少。有丝分裂出口网络（男性）， 类似RAS的GTPase信号传导级联和河马途径的酵母同源物为您提供了独特的机会 研究这个问题。在男人中，相同的核心信号组件以不同的方式运作 不同的发展轨迹。在酵母有丝分裂中，通过不对称细胞分裂发生 这些人被称为萌芽，将脚手架脚手架上的纺锤体体（SPB，相当于中心体的酵母） 并通过其GTPase TEM1响应主轴位置。在减数分裂期间，萌芽被抑制和 因此，无需感知纺锤体位置，男人的信号不再是在SPB处组织的，目前尚不清楚 男性激活是否仍需要TEM1及其可能响应的信号。理解 在不同的细胞环境下，男人的适应，该提案将检验以下假设。 由MEN激酶Cdc15的不同激活机制（TEM1的效应子激酶）的不同激活机制部分启用 在有丝分裂和减数分裂之间（目标1）。与男性核心空间组织的急剧变化相反 有丝分裂和减数分裂之间的成分，男性的效应蛋白，磷酸酶CDC14，仍然存在 在有丝分裂和减数分裂激活之前，在核中隔离。实际上，这种核定位 CDC14从酵母到人都是保守的。核仁中cdc14的隔离可以起作用1） 确保在激活之前严格抑制CDC14的磷酸酶活性，或2）将Cdc14定位到 核仁中的特定底物去磷酸化。要揭示维持这一点的选择压力 CDC14保守的核定位，该提案将通过隔离来检查这两个假设 细胞中其他地方的Cdc14首先表征酵母中的后果，然后在哺乳动物细胞中表征 （目标2）。两个目标中的实验将在K99阶段启动，这还包括培训 新实验系统（例如酵母减数分裂和哺乳动物细胞）的候选者以及 定量显微镜，接近标记和光遗传学的开发和实施。此外， 候选人召集了一个杰出的心理团队，以科学的态度建议她促进进步 该项目的工作，并准备向独立调查员过渡。在一起，这个建议将 为了解进化/适应和 细胞信号传导的空间组织。