Cellular dynamics in division, motility and evolutionary adaptation

 描述(由申请人提供)：本研究项目的总体目标是从分子和数量两个方面从根本上了解真核细胞如何分裂、移动和适应环境。这些本质上是系统层面的问题，我们计划采取一种完全集成的方法，将全细胞定量观察和数学建模与阐明分子机制的传统结构-功能分析相结合。除了揭示基本原则的目标外，我们还将积极寻找机会，将基础研究的新见解应用于改善人类健康。这项由Mira赠款支持的工作分为三个一般领域，由三个独立的NIGMS赠款提供资金：i)细胞不对称分裂是通过细胞分裂产生不同类型或命运的主要发育机制，经常被干细胞用来满足自我更新和分化。我们的工作将集中在使用发芽酵母作为模型系统，以了解质膜的蛋白质和脂肪成分如何自组织来驱动细胞对称性的破坏和细胞极性的建立；以及细胞极性轴如何指导分子决定因素的分离，这些决定因素指定了每个细胞分裂的两个后代细胞的复制年龄。特别是，我们将揭示内质网和线粒体在蛋白质组损伤的巩固和分离中的作用，并检验这一功能与细胞不对称分裂期间线粒体生物发生的不对称性直接相关的假设。这项研究有望在未来扩展到哺乳动物干细胞。Ii)细胞运动是动物生物体发育和生理所必需的一个关键过程，它还取决于细胞的极性和细胞骨架的动态组装。拟议的部分工作将作为PO1与几个在电子冷冻显微镜、肌动蛋白生物化学以及细胞动力学和力学数学建模方面具有领先专业知识的实验室合作进行。我的团队将使用小鼠基因技术、原代细胞培养和活体成像来探索树突状肌动蛋白成核在细胞运动中的作用。我们的集体GAL是为了实现对肌动蛋白聚合和细丝组织如何产生推动前沿定向突起的力量的定量了解。第二个目标是使用小鼠的原代运动细胞来洞察细胞运动机制在不同机械和几何环境中的多样性和可塑性。3)进化性是生物系统的基本能力，使细胞和有机体能够经历基因变化，以适应内部或环境的扰动。细胞水平上的进化性是我们研究的重点，也是癌细胞和病原微生物逃避宿主免疫系统或对治疗产生抵抗力的能力的基础。我们提出的工作旨在破译染色体拷贝数变异或非整倍体是如何由于染色体不稳定而产生戏剧性的表型变化并驱动快速细胞适应的。我们还将调查染色体剂量不平衡造成的一般性缺陷，以及如何利用这些缺陷进行抗癌治疗。

 DESCRIPTION (provided by applicant): The overall goal of this research project is to understand, on a fundamental level, in both molecular and quantitative terms, how eukaryotic cells divide, move, and adapt to their environment. These are inherently systems-level problems, for which we plan to take a fully integrated approach that combines whole-cell quantitative observation and mathematical modeling with traditional structure-function analysis that illuminates molecular mechanisms. In addition to the goal of uncovering fundamental principles, we will actively seek opportunities to apply new insights from basic research to the improvement of human health. The work to be supported by this MIRA grant falls into three general areas that have been funded by three independent NIGMS grants: I) Asymmetric cell division is a major developmental mechanism in the generation of diverse cell types or fates through cell division and is frequently used by stem cells to satisfy both self-renewal and differentiation. Our work will be focused on using the budding yeast as the model system to understand how protein and lipid components of the plasma membrane self-organize to drive cellular symmetry breaking and the establishment of cell polarity; and how the axis of cell polarity directs the segregation of molecular determinants that specify the replicative age of the two progeny cells of each cell division. In particular, we will unravel the role of ER and mitochondria in the consolidation and segregation of proteome damage, and test the hypothesis that this function is directly linked to an asymmetry in mitochondria biogenesis during asymmetric cell division. This research is envisioned to be expanded to mammalian stem cells in the future. II) Cell motility is a critical process required for the development and physiology f animal organisms that also depends on cell polarity and dynamic assembly of the cytoskeleton. Part of the proposed work will be conducted as a PO1 collaborative effort with several labs with leading expertise in electron cryo-microscopy, actin biochemistry, and mathematical modeling of cell dynamics and mechanics. My group will use mouse genetic techniques, primary cell culture and live imaging to probe the role of dendritic actin nucleation in cell motility. Our collective gal is to achieve a quantitative understanding of how actin polymerization and filament organization produce the force driving directional protrusion of the leading edge. A second goal is to use primary motile cells from mice to gain insights into the diversity and plasticity of cell motility mechanisms in different mechanical and geometrical environments. III) Evolvability is the fundamental capacity of biological systems that enables cells and organisms to undergo genetic changes to adapt to internal or environmental perturbations. Evolvability on the cellular level, th focus of our research, also underlies the ability of cancer cells and pathogenic microbes to elude the host immune system or become resistant to therapeutic treatments. Our proposed work is designed to decipher how chromosome copy number variation, or aneuploidy, as a result of chromosome instability produces dramatic phenotypic change and drives rapid cellular adaptation. We will also investigate general defects caused by chromosome dosage imbalance and how such deficiencies may be exploited for anti-cancer treatment.