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

基本信息

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
项目类别：
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

项目摘要

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.

项目概要通过信号级联感知和处理信息是细胞生命的重要组成部分。 MAP 激酶和 Hippo 通路等信号级联在真核生物中普遍存在尽管这些途径已被充分研究，但它们是如何进化的。对于承担新功能和适应新输入的有丝分裂退出网络（MEN）仍然知之甚少。 Ras 样 GTPase 信号级联和 Hippo 途径的酵母同源物，提供了独特的机会研究这个问题，在 MEN 中，相同的核心信号组件以不同的方式运行。在酵母有丝分裂过程中，通过不对称的细胞分裂发生不同的发育轨迹。称为出芽，MEN 被搭建在纺锤体极体上（SPB，相当于酵母的中心体）并通过其 GTPase Tem1 对纺锤体位置作出反应在减数分裂过程中，出芽受到抑制，并且因此无需感测纺锤体位置，MEN 信号不再在 SPB 上组织，目前还不清楚 MEN 激活是否仍需要 Tem1 以及它可能响应什么信号。 MEN 在不同的细胞环境下的适应，该提案将测试这种适应的假设部分是由 MEN 激酶 Cdc15（Tem1 的效应激酶）的不同激活机制实现的，有丝分裂和减数分裂之间的差异（目标 1），与 MEN 核心空间组织的巨大变化形成对比。有丝分裂和减数分裂之间的组成部分，MEN 的效应蛋白，即磷酸酶 Cdc14，仍然存在在有丝分裂和减数分裂激活之前被隔离在核仁中。 Cdc14 从酵母到人类都是保守的。Cdc14 隔离在核仁中可以发挥以下作用：1) 到确保在激活之前严格抑制 Cdc14 的磷酸酶活性或 2) 将 Cdc14 定位到去磷酸化核仁中的特定底物，以揭示维持这种情况的选择压力。由于 Cdc14 的保守核仁定位，该提案将通过隔离来检验这两个假设 Cdc14 在细胞的其他地方，并首先在酵母中，然后在哺乳动物细胞中表征后果（目标 2）。这两个目标的实验将在 K99 阶段启动，其中还包括培训新实验系统的候选人，例如酵母减数分裂和哺乳动物细胞，以及定量显微镜、邻近标记和光遗传学的开发和实施。候选人组建了一支优秀的导师团队，为她提供科学的建议，以促进进步该提案将共同帮助她做好向独立调查员过渡的准备。为了解进化/适应和理解进化/适应的独立研究生涯奠定坚实的基础细胞信号传导的空间组织。