Collaborative Research: Modeling Spatiotemporal Control of EGFR-ERK Signaling in Gene-edited Cell Systems

在这个项目中，研究人员将开发一个新的实验和计算平台，以回答长期存在的生物学问题，即细胞受体在各种亚细胞区室之间移动时如何产生生化信号。通过帮助定量解决某些明显相互矛盾的观察结果，这些观察结果最近在以前被认为是很好理解的生物系统中进行，该项目将从根本上增加对细胞信号传导基本机制的新理解，这些机制可能对细胞生物学中的许多受体系统产生影响。此外，由于受体及其产生的生化信号在几乎每个生物过程中都发挥着广泛的重要作用，所获得的新的定量理解将最终影响正在进行的优化设计受体介导的信号传导的努力。该项目还包括一套广泛而详细的综合教育目标，这些目标利用该项目的具体科学目标和活动，以覆盖不同培训阶段和不同背景的学生。这些教育和外展活动涉及在合作机构现有计划的基础上进行创新，以及针对更大受众的新外展工作的创建，例如高中学生的暑期科学学院以及与佛罗里达州坦帕的科学与工业博物馆合作开发细胞信号的实时互动计划。配体与受体酪氨酸激酶结合后产生的生化信号传导伴随着受体聚集和内化或内吞作用。虽然几十年来已经理解内吞作用使细胞能够降解或回收受体，但内吞作用最终如何影响下游信号传播的问题仍然是开放的。例如，即使对于高度研究的表皮生长因子受体（EGFR），文献也包含高度引用但相互矛盾的报告，这些报告得出结论认为EGFR内吞作用通过细胞外调节激酶（ERK）途径促进或阻碍下游信号传导。在这个项目中，研究人员将探索这样一个假设，即时空信号调节机制的内在复杂性为两个答案创建了参数空间，这取决于细胞环境。受体运输和信号传导系统的复杂性不能完全解剖，但是，如果不整合定量的实验测量，忠实地反映细胞生物学与时空计算模型。因此，该项目的总体目标是将基因编辑细胞系统的新型活细胞成像与以前所未有的细节捕获系统复杂性的机制模型相结合，以解决先前提到的各种相互冲突的报告，以及最近令人惊讶的观察结果，即通常认为在信号转导过程中保持复杂性的某些蛋白质可能通过运输过程变得物理分离。最终，基因编辑细胞系统、定量活细胞成像和生化测量以及时空计算模型的整合将带来一个全新的定量平台，以回答EGFR和其他受体信号系统的这类问题。

In this project, the investigators will develop a new experimental and computational platform to answer the longstanding biological question of how cellular receptors generate biochemical signals as they move among various subcellular compartments. By helping to quantitatively resolve certain apparently conflicting observations that have recently been made within a biological system previously thought to be well understood, this project will add fundamentally new understanding of basic mechanisms of cell signaling that may have implications across numerous receptor systems in cell biology. Moreover, due to the broadly important role that receptors, and the biochemical signals they generate, play in virtually every biological process, the new quantitative understanding gained will ultimately impact ongoing efforts to optimally engineer receptor-mediated signaling. This project also includes a broad and detailed set of integrated educational objectives that leverage the specific scientific objectives and activities of this project to reach students at different training stages and from diverse backgrounds. These education and outreach activities involve innovation upon existing programs at the partnering institutions as well as the creation of new outreach efforts that will target larger audiences, such as a summer academy of science for high school students and a collaboration with the Museum of Science and Industry in Tampa, FL to develop a live interaction program on cell signaling. The biochemical signaling that results upon ligand binding to receptor tyrosine kinases is accompanied by receptor clustering and internalization, or endocytosis. While it has been understood for decades that endocytosis enables cells to degrade or recycle receptors, the question of how endocytosis ultimately impacts downstream signal propagation remains wide open. For example, even for the highly studied epidermal growth factor receptor (EGFR) the literature contains highly cited, yet conflicting reports that conclude that EGFR endocytosis either promotes or impedes downstream signaling through the extracellular regulated kinase (ERK) pathway. In this project, the investigators will explore the hypothesis that the intrinsic complexity of the spatiotemporal signaling regulatory mechanisms creates parameter spaces for both answers to be true depending on the cellular context. The complexity of the receptor trafficking and signaling system cannot be fully dissected, however, without integrating quantitative experimental measurements that faithfully reflect cell biology with spatiotemporal computational models. Accordingly, the overarching goal of this project is to combine novel live-cell imaging of gene-edited cell systems with mechanistic models that capture system complexity with unprecedented detail to resolve the kinds of conflicting reports previously mentioned, as well as more recent surprising observations that certain proteins conventionally thought to remain in complex during signal transduction may become physically separated through trafficking processes. Ultimately, the proposed integration of gene-edited cell systems, quantitative live-cell imaging and biochemical measurements, and a spatiotemporal computational model will lead to an entirely new quantitative platform to answer these kinds of questions for EGFR and other receptor signaling systems.