Excitable Networks in Directed Cell Migration

我们正在研究定向细胞迁移的分子机制，这是健康和 疾病，使用网柄菌作为发现工具，为我们对中性粒细胞、巨噬细胞和 上皮细胞。我们工作模型的核心是耦合的信号转导和细胞骨架 兴奋性网络，称为STEN和CEN，推动运动性。Sten集成了来自 定向传感和极性网络，实现定向迁移。在上一次授权期内，我们 发现突起由一波耦合的Sten-CEN活动和操纵Sten-CEN活动控制 膜内表面带负电荷的脂类可以改变网络兴奋性和控制细胞 行为。Sten-CEN的概念在哺乳动物细胞中是保守的，并且网络被高度激活 在转化的细胞中，增强运动性和巨噬细胞吞噬。因为这些工艺需要香叶醇 他汀类药物会导致癌细胞饥饿。最后，我们发现囊泡内化于 回缩的突起将“背部”的成分带到细胞的后部，从而形成了极性。 不同的细胞突起如何依赖于Sten-CEN的设定点/阈值？我们是 结合成像、合成生物学和计算研究来证明伪足类动物， 片状脂类、形成吞噬体体等在光谱上密切相关，并可相互转换。我们 将表明，活动和对急性分子扰动的反应的时空模式是 在这些突起上是一致的，在传播Sten-CEN波时是平行的。 如何解释STEN和CEN活动的非凡协调？猜测这一指控 膜的内部小叶是一个组织者，我们正在设计直接监控电荷的方法 在局部区域；2)确定阴离子脂类如何瞬时减少；3)局部操纵电荷 光遗传系统；4)研究关键蛋白质的位置如何受表面电荷的调节。 Sten阈值降低是转化细胞的普遍属性吗？它能被利用吗？致信地址 这个问题，我们正在1)比较阈值指标，如传播波，与 一系列日益转移的细胞系和有机物中的巨噬细胞吞噬和他汀类药物敏感性；2) 鉴定Sten中必需的Geranylgeranylated蛋白；3)基因工程细胞增加 使癌细胞正常化的阈值或进一步降低诱导细胞死亡的阈值。 在细胞两极对Sten和CEN的控制如何调节定向感觉和极性？第一, 使用一种新的抑制试验，我们正在筛选缺乏激酶和底物的细胞，以识别全球 抑制剂。其次，我们正在研究各种条件下的膜流动，以追求我们的“反转” 喷泉“模型，它与认为膜从前到后流动的替代模型相一致。 1

We are investigating molecular mechanisms of directed cell migration, a critical process in health and disease, using Dictyostelium as a discovery tool to inform our studies of neutrophils, macrophages, and epithelial cells. At the core of our working model are coupled Signal Transduction and Cytoskeletal Excitable Networks, referred to as STEN and CEN which drive motility. The STEN integrates inputs from directional sensing and polarity networks to bring about directed migration. In the last grant period, we found that protrusions are governed by waves of coupled STEN-CEN activities and that manipulation of negatively charged lipids on the inner face of the membrane can alter network excitability and control cell behavior. The STEN-CEN concept is conserved in mammalian cells and the networks are hyperactivated in transformed cells, augmenting motility and macropinocytosis. Since these processes require geranyl geranylation, statins cause starvation of cancer cells. Finally, we found that vesicles internalized from retracting protrusions carry “back” components to the rear of the cell contributing to polarity. How do diverse cellular protrusions depend on the setpoint/threshold of STEN-CEN? We are combining imaging, synthetic biological, and computational studies to prove that pseudopods, lamellipods, forming phagosomes, and so on are closely related on a spectrum and interconvertible. We will show that spatiotemporal patterns of activities and responses to acute molecular perturbations are consistent across these protrusions and parallel those established in propagating STEN-CEN waves. What explains the extraordinary coordination of activities in STEN and CEN? Surmising that charge on the inner leaflet of the membrane is an organizer, we are 1) designing methods to directly monitor charge in local regions; 2) determining how anionic lipids transiently decrease; 3) manipulating charge locally with optogenetic systems; 4) examining how the location of key proteins is regulated by surface charge. Is lowered STEN threshold a general property of transformed cells and can it be exploited? To address this question, we are 1) comparing threshold indicators, such as propagating waves, with macropinocytosis and statin sensitivity in a series of increasingly metastatic cell lines and organoids; 2) identifying the essential geranylgeranylated proteins in STEN; 3) genetically engineering cells to increase threshold to normalize cancer cells or further decrease threshold to induce cell death. How does control of STEN and CEN at the cell poles mediate directional sensing and polarity? First, using a novel suppression assay, we are screening kinase and substrate deficient cells to identify global inhibitors. Second, we are studying membrane flow in a variety conditions to pursue our “reverse fountain” model and it reconcile with alternate models that argue membrane flows from front to back. 1