Decoding dynamic interplay between signaling and membranes in chemotaxis bymolecular actuators

父母R35补助金 “通过分子生物学方法解码信号传导和趋化性膜之间的动态相互作用 执行器” 提案摘要 趋化性发生在许多关键生理事件中，包括血管生成， 胚胎发育和伤口愈合。它也有助于疾病进展， 病理状况如癌症转移和关节炎。目前提案的目标是 是揭示生物化学反应和物理特性，如膜曲率， 变形和装配阶段，相互作用，实现动态，准确，但 高效的细胞迁移。趋化性主要是从信号的角度来理解的 转导，而膜的物理性质是否以及如何发挥作用，以及它们如何相互作用 与信号转导的关系仍不清楚。通过新开发和实施一系列 的分子执行器，可以直接探测膜的性能与高时空 在活泼的迁移细胞内的精确性，我们将揭示信号转导和 膜力学 是什么分子机制导致局部膜弯曲发展成 丝状伪足和片状伪足在感受化学引诱物时，细胞通过经历 不对称的膜变形，由前部的丝状伪足和片状伪足组成， 后部的膜收缩。我们最近发现，曲率敏感蛋白是一种缺失的， 连接肌动蛋白细胞骨架和细胞膜。这一结果使我们假设肌动蛋白 机械和曲率传感和重塑蛋白质，当在一个适当的调制， 反馈回路足以产生所需类型的膜变形， 板状伪足和丝状伪足。因此，我们将鉴定Rho GTP酶、肌动蛋白 调节子和BAR蛋白及其分子逻辑，它们负责形成 丝状伪足和片状伪足。 迁移细胞中的信号成分如何响应膜变形？ 迁移细胞在质膜和核上表现出动态的形态学变化 包膜的“结果”的细胞骨架重排调节的信号成分。 探讨细胞膜变形与细胞骨架和信号传导的可能性 组件，我们将部署分子执行器，可以直接变形膜。我们将 然后定量随后出现的信号传导成分的活性， 激酶、PI 3 K和小GTP酶，以及转录因子如雅普和Elk。 相分离的细胞骨架生物分子凝聚物如何在 膜变形？肌动蛋白网络可以经历生物分子缩合物的形成， 由于肌动蛋白调节剂之间的弱多价相互作用，质膜。审查 这种相分离事件的生理重要性，我们将采用分子技术 来组装或拆卸冷凝物。这些行动将独特地实现收益-或 不改变分子成分的量的功能丧失操作;什么是 改变的是它们的物理组装状态。我们将描述细胞迁移表型， 并且在部署相位操纵之后。

Parent R35 grant “Decoding dynamic interplay between signaling and membranes in chemotaxis by molecular actuators” Proposal Summary Chemotaxis occurs during a number of key physiological events including angiogenesis, embryonic development and wound healing. It also contributes to disease progression in pathological conditions such as cancer metastasis and arthritis. The goal of the current proposal is to reveal how biochemical reactions and physical characteristics, such as membrane curvature, deformation, and assembly phase, interact with one another in achieving dynamic, accurate yet highly efficient cell migration. Chemotaxis has been understood mainly in the perspective of signal transduction, while if and how physical properties of membranes play a role, and how they interact with signal transduction remain largely unknown. By newly developing and implementing a series of molecular actuators that can directly probe membrane properties with high spatio-temporal precision inside lively migrating cells, we will reveal an interplay between signal transduction and membrane mechanics. What molecular mechanisms generate local membrane curvatures developing into filopodia and lamellipodia? In sensing chemoattractants, cells polarize by undergoing asymmetric membrane deformation consisting of filopodia and lamellipodia at the front, and membrane retraction at the rear. We recently found that curvature-sensitive proteins are a missing link between actin cytoskeleton and membranes. The result made us hypothesize that actin machinery and curvature sensing and remodeling proteins, when properly modulated in a feedback loop, are sufficient to produce desired types of membrane deformations such as lamellipodia and filopodia. We will thus identify a particular combination of Rho GTPases, actin regulators, and BAR proteins, and the molecular logic thereof, that are responsible for formation of filopodia and lamellipodia. How do signaling components in migrating cells respond to membrane deformation? Migrating cells exhibit dynamic morphological changes at plasma membranes and nuclear envelopes “as a consequence” of cytoskeletal rearrangement regulated by signal components. To explore a possibility that membrane deformation talks back to cytoskeletal and signal components, we will deploy molecular actuators that can directly deform membranes. We will then quantify subsequently emerging activity of signaling components such as receptor tyrosine kinases, PI3K, and small GTPases, as well as transcription factors such as YAP and Elk. How does the phase-separated cytoskeletal biomolecular condensate play a role in membrane deformation? Actin networks can undergo formation of biomolecular condensates at the plasma membrane due to weak multivalent interactions among actin regulators. To examine the physiological importance of such phase separation events, we will adapt molecular techniques to assemble or disassemble the condensates. These operations will uniquely achieve gain- or loss-of function manipulations without altering an amount of the molecular constituents; what is altered is their physical assembly status. We will characterize cell migration phenotypes before and after deploying phase manipulations.