细胞迁移是最重要的生命活动之一，在胚胎发育，器官形成，损伤修复及免疫应答等过程中都发挥着重要作用。在趋化性运动中，趋化因子通过激活一系列胞内信号转导通路来完成细胞形态和位置的改变。信号分子的极性定位或特异激活是细胞定向迁移的重要步骤，但其调控机制尚不明确。在模式生物Dictyostelium细胞中，在细胞质膜的前或后端特异定位的信号分子可响应均匀场趋化信号刺激而发生瞬时的定位改变。基于极性信号蛋白的这一动态特征，在本项目中我们选取定量蛋白质组学作为研究手段，通过比较趋化因子cAMP刺激前后Dictyostelium细胞膜蛋白组分的变化，系统筛选可以被瞬时招募至细胞质膜或从质膜上解离的外周膜蛋白，从而鉴定在细胞前端或后端极性定位的新的信号分子，进而发现新的细胞定向运动的调控因子并对其定位机制和细胞功能进行深入研究，以期进一步理解细胞极性建成和定向运动的分子生物学机制。

Cell migration plays a critical role in a variety of biological processes, including embryogenesis, organ formation, immune response and regenerative processes such as wound healing. The binding of chemoattractant to receptors on the plasma membrane triggers cell migration and polarity reformation by activating a complex signal transduction network. The asymmetric distribution or activation of signaling proteins is essential during this process, however the underlying regulatory mechanisms are still unclear. In the model organism Dictyostelium discoideum, upon stimulation with uniform chemoattractants, known leading or lagging edge signaling proteins often display characteristic behaviors by transiently translocating to or falling off from the plasma membrane, respectively. Using quantitative proteomics approach, we design experiments to systematically isolate peripheral membrane proteins that display similar behaviors upon stimulation. By characterizing these proteins, we aim to identify new regulators of chemotaxis. Further elucidation of the molecular basis of their polarized distribution and cellular function will likely provide new insights into the molecular mechanisms of polarity establishment and cell migration.