Multicomponent mechanochemical regulation of actin filament end dynamics

肌动蛋白丝末端动力学的多组分机械化学调节

• 批准号: 10455672
• 负责人: Shashank Shekhar
• 金额: $ 38.71万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2026-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10455672
• 关键词: Acceleration; Actin-Binding Protein; Actins; Adrenergic alpha-Antagonists; Alzheimer' s Disease; Amyotrophic Lateral Sclerosis; Behavior; Binding; Binding Proteins; Biochemical; Biophysics; Cell division; Cells; Complex; Deformity; Development; Disease; Disseminated Malignant Neoplasm; Ecosystem; Endocytosis; Enhancers; Filament; Goals; Growth; Human; Immune; Individual; Limb structure; Microfilaments; Microfluidics; Microscopic; Molecular; Neurologic; Parkinson Disease; Phagocytosis; Physiological; Process; Proteins; Regulation; Research; Signal Transduction; Site; Structure; Vision; Work; cell motility; cofilin; combat; depolymerization; developmental disease; experimental study; mathematical model; mechanical force; mechanical signal; molecular imaging; nervous system disorder; novel therapeutics; single molecule; wound healing

ABSTRACT Cellular actin dynamics are essential in a number of key processes such as cell migration, wound healing, cell division and endocytosis. Physiological actin dynamics arises from a complex interplay between protein machineries that influence either the assembly of new actin structures or the disassembly of existing actin structures. Over the last few decades, a plethora of proteins regulating actin dynamics in cells have been identified and individually characterized. However, we still do not fully understand how these proteins work together in multiprotein ecosystems and how they give rise to emergent behavior that cannot be predicted simply by adding their known individual activities. Over the last few years, I have discovered several such multicomponent activities. I showed that an enhancer (formin) and a blocker (capping protein) of actin growth can simultaneously bind the same site on an actin filament, in the process initiating their own dynamic exchanges at filament ends. I also accomplished the first direct microscopic demonstration of a long-predicted but never observed acceleration of pointed-end depolymerization of actin filaments by cyclase-associated protein (CAP) and cofilin. Over the next five years, our goal is to uncover how multicomponent biochemical signals and mechanical signals get integrated at the scale of individual actin filaments. We will build on our ground-breaking discoveries by investigating other proteins that we have identified, which either directly bind filament ends or via other end-binding proteins. We will also investigate how mechanical forces alter biochemical interactions of actin binding proteins with actin filaments. To do this, we will employ a unique combination of microfluidics-assisted (mf-TIRF) and multispectral single molecule imaging that I have pioneered over the last few years. We will combine biochemical and biophysical experiments with mathematical modelling. My vision is that a better understanding of molecular mechanisms underlying actin dynamics will pave the way for development of new therapies to combat human ailments like Amyotrophic Lateral Sclerosis (ALS), metastatic cancer, neurological (e.g. Alzheimer's disease and Parkinson's diseases) and developmental disorders (e.g. limb deformities) that are caused due to abnormalities related to actin dynamics.

抽象的 细胞肌动蛋白动力学在许多关键过程中至关重要，例如细胞迁移、伤口愈合、细胞 分裂和内吞作用。生理肌动蛋白动力学源于蛋白质之间复杂的相互作用 影响新肌动蛋白结构组装或现有肌动蛋白分解的机器 结构。在过去的几十年里，大量调节细胞肌动蛋白动力学的蛋白质已被研究出来。 识别并单独表征。然而，我们仍然不完全了解这些蛋白质是如何工作的 多蛋白生态系统中的共同作用以及它们如何引起无法简单预测的紧急行为 通过添加他们已知的个人活动。在过去的几年里，我发现了几个这样的 多组成部分的活动。我证明了肌动蛋白生长的增强剂（福尔马林）和阻断剂（加帽蛋白） 可以同时结合肌动蛋白丝上的同一位点，在此过程中启动它们自己的动态交换 在灯丝末端。我还完成了对长期预测但从未实现的第一次直接微观演示 观察到环化酶相关蛋白 (CAP) 加速肌动蛋白丝的尖端解聚 和科菲林。在接下来的五年中，我们的目标是揭示多组分生化信号和 机械信号在单个肌动蛋白丝的尺度上进行整合。我们将在我们的突破性基础上再接再厉 通过研究我们已识别的其他蛋白质而发现，这些蛋白质直接结合细丝末端或通过 其他末端结合蛋白。我们还将研究机械力如何改变肌动蛋白的生化相互作用 与肌动蛋白丝结合的蛋白质。为此，我们将采用微流体辅助的独特组合 （mf-TIRF）和多光谱单分子成像是我在过去几年中开创的。我们将 将生物化学和生物物理实验与数学建模相结合。我的愿景是更好 了解肌动蛋白动力学的分子机制将为开发新的药物铺平道路 对抗肌萎缩侧索硬化症 (ALS)、转移性癌症、神经系统疾病等人类疾病的疗法 （例如阿尔茨海默病和帕金森病）和发育障碍（例如肢体畸形） 是由于肌动蛋白动力学异常引起的。