Molecular Mechanisms of Cell Migration

细胞迁移的分子机制 项目总结： 细胞外基质(ECM)信号的识别对许多发育和动态平衡过程至关重要， 而对线索的曲解是转移等疾病的基础。细胞通过延伸寻找ECM线索 以肌动蛋白为基础的突起，结合ECM并形成锚，帮助它们向前推进。然而，人们对此知之甚少 关于将突起的ECM探测转换为定向的决策过程和信号通路 细胞迁移。许多传统的显微镜研究认为，突起上均匀覆盖着 随机扩散随机结合ECM的未结合的ECM受体。有了我们密集的新方法- 现场单分子超分辨显微镜，我们发现了一条未结合的ECM的集中带 位于突起前部的受体，具有受体组织的特有分子模式， 机动性和功能化。这些模式取决于细胞的突起活动和特定的受体。 细胞质结合域，表明细胞质相互作用，仅在单分子水平上可见 调节未结合的整合素的组织方式，为探测细胞外基质做准备。在本提案中，我们将 定义通过集成将ECM探测转换为定向细胞迁移的细胞决策流程 细胞外基质受体群体的组织、相互作用和功能化的分子测量 粘连组装、肌动蛋白调节通路和突起活动的细胞测量。我们将：1) 定义创建未结合的ECM受体组织的全球时空模式的机制， 细胞突起前面的移动性和构象，调节突起的功能化 探测ECM；2)识别与ECM受体结合的信号通路，这些信号通路用于分离转换决定 细胞外基质从决定继续通过肌动蛋白细胞骨架探测细胞外基质进入定向迁移 动力学。这些研究将直接有助于我们理解细胞对许多ECM线索的识别 发展和动态平衡过程，以及我们对线索误解的理解，这是 是转移等疾病的基础。

Molecular Mechanisms of Cell Migration Project summary: Recognition of extracellular matrix (ECM) cues is critical to many developmental and homeostatic processes, and misinterpretation of cues underlies diseases such as metastasis. Cells probe for ECM cues by extending actin-based protrusions to bind ECM and form anchors to help them move forward. However, little is known about the decision processes and signaling pathways that convert ECM probing by protrusions into directed cell migration. Many conventional microscopy studies posit that protrusions are uniformly covered with randomly diffusing unbound ECM receptors that stochastically bind ECM. With our new approach of dense- field single molecule super-resolution microscopy, we have discovered a concentrated band of unbound ECM receptors at the front of protrusions that have characteristic molecular patterns of receptor organization, mobility, and functionalization. These patterns depend on both cellular protrusive activity and specific receptor cytoplasmic binding domains, indicating that cytoplasmic interactions, visible only at the single molecule level regulate how unbound integrins are organized in preparation for probing for ECM. In this proposal we will define the cellular decision processes that convert ECM probing into directed cell migration by integrating molecular measures of the organization, interaction, and functionalization of populations of ECM receptors with cellular measures of the assembly of adhesions, actin regulatory pathways, and protrusive activity. We will: 1) Define mechanisms that create the global spatial-temporal patterns of unbound ECM receptor organization, mobility, and conformation at the front of cell protrusions that regulate the functionalization of protrusions to probe ECM; 2) Identify signaling pathways that bound ECM receptors use to separate the decision to convert an ECM cue into directed migration from the decision to continue to probe the ECM through actin cytoskeletal dynamics. These studies will directly contribute to our understanding of cell recognition of ECM cues in many development and homeostasis processes, as well as our understanding of the misinterpretation of cues, which underlies diseases such as metastasis.