Cell Signaling and Cell Decisions

项目摘要/摘要 哺乳动物细胞必须移动和增殖以维持和再生组织并防御自身 病原体，但增加移动或增殖的突变也可能导致癌症。茎、祖先和 分化的细胞通常不活动和静止，但不断整合细胞-细胞接触，细胞-基质接触， 和受体输入，并做出两个不同的决定(通常是相互关联的)，它们是否应该开始 如果需要，移动并开始扩散。有几个挑战阻碍了对这两个问题的理解 决策过程。动物的遗传方法不能轻易地处理大量的 信号传递过程而培养细胞的生化分析往往导致不确定的结果，因为 难以同步细胞并解决细胞中何时何地发生信号的问题。只进行单细胞分析 可以解决控制这些复杂决策的空间和时间信号反馈。我们的实验室 已经开发出急需的荧光单细胞活性报告，快速扰动策略，以及 自动显微镜和分析方法来研究这两个基本的决策过程。 为了理解两极分化和移动的决定，我们将使用我们开发的新工具来探索 外部受体酪氨酸激酶信号和细胞-细胞和细胞-基质接触协同控制启动 以及维持细胞信号和肌动蛋白组织的梯度，以及细胞如何在局部引导信号 渐变和运动。为了了解扩散的决定，我们将调查竞争 决定在质膜上这些相同的信号输入如何控制两个 细胞核中细胞周期蛋白-CDK激酶的活性，探索细胞如何控制仍然可以 在细胞致力于更晚的增殖之前被逆转许多小时，并解决这个相同的决定 进程协调复制和DNA复制起点的许可，以防止基因组不稳定和 细胞死亡。我们工作的结果将是从数量、分子和机制上理解 哺乳动物细胞整合信号以决定开始移动和增殖，以及突变是如何实现的 这些增殖和迁移决定的失调会导致癌症和其他疾病。

PROJECT SUMMARY/ABSTRACT Mammalian cells must move and proliferate to maintain and regenerate tissues and defend themselves against pathogens, but mutations that increase movement or proliferation can also cause cancer. Stem, progenitor, and differentiated cells are often non-motile and quiescent but keep integrating cell-cell contacts, cell-matrix contacts, and receptor inputs, and make two distinct decisions (that are often connected) whether they should start to move and start to proliferate if needed. Several challenges have prevented an understanding of these two decision processes. Genetic approaches in animals cannot readily tackle the co-regulation of large numbers of signaling processes while biochemical analysis of cultured cells often leads to inconclusive results due to the difficulty to synchronize cells and resolve when and where in a cell signaling occurs. Only single cell analysis can resolve the spatial and temporal signaling feedbacks controlling these complex decisions. Our laboratory has developed critically needed fluorescent single-cell activity reporters, rapid perturbation strategies, and automated microscopy and analysis methods to investigate these two fundamental decision processes. To understand the decision to polarize and move, we will use the new tools we developed to explore how external receptor tyrosine kinase signals and cell-cell and cell-matrix contacts synergistically control the initiation and maintenance of gradients in cell signaling and actin organization, and how cells locally direct the signaling gradients and movement. To understand the decision to proliferate, we will investigate the competition mechanism that determines how these same signal inputs at the plasma membrane control the activation of two cyclin-Cdk kinase activities in the nucleus, explore how cells control a proliferation decision process that can still be reversed for many hours before cells commit to proliferate much later, and resolve how this same decision process coordinates the licensing of origins of replication and DNA replication to prevent genome instability and cell death. The outcome of our work will be a quantitative, molecular, and mechanistic understanding of how mammalian cells integrate signals to make decisions to start to move and proliferate, and how mutations that dysregulate these proliferation and migration decisions can cause cancer and other diseases.