Actin cytoskeleton from nucleus to organism

肌动蛋白细胞骨架从细胞核到生物体

• 批准号: 10457940
• 负责人: Anna Sokac
• 金额: $ 38.2万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-15 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10457940
• 关键词: Actin-Binding Protein; Actins; Actomyosin; Back; Cell Nucleus; Cell Shape; Cell physiology; Cells; Congenital Abnormality; Contracts; Cytoplasm; Cytoskeleton; Disease; Drosophila genus; Embryo; Embryology; Environment; Event; Failure; Fever; Gene Expression; Genes; Genetic; Genetic Transcription; Goals; Health; Homeostasis; Kinetics; Mediator of activation protein; Messenger RNA; Methods; Microfilaments; Molecular; Morphogenesis; Myosin S-2; Organism; Outcome; Pharmaceutical Preparations; Phase; Phenotype; Process; Proteins; Resolution; Risk; Role; Shapes; Signal Transduction; Stress; System; Testing; Textbooks; Time; Tissues; Work; base; biological adaptation to stress; genetic regulatory protein; interest; live cell imaging; mechanical properties; scaffold; single molecule; stem

PROJECT SUMMARY/ABSTRACT Textbooks teach us that actin filaments give cells their shape, and that a “parts list” of proteins drives actin remodeling when cells change shape. But what is missing from this simple telling is a holistic understanding of how upstream gene expression and signaling control actin remodeling, how different proteins work together to remodel actin, and how downstream cell shape change is converted into timely and reliable organismal out- comes. Because actin-based failures can stem from events before, during and after remodeling, we need an integrated understanding to make sense of actin’s critical role in health and disease. To obtain this kind of “whole picture” view of actin, my lab studies cellularization, the first tissue-building event in Drosophila embryos. We developed this simple experimental system so that we can study the actin remodeling that drives cellularization, while also relating that remodeling to upstream events at the level of gene expression and signaling, and downstream outcomes including morphogenetic fidelity and embryonic viability. Our methods combine Drosophila genetics and embryology with quantitative live-cell imaging of mRNAs, actin, and actin regulatory proteins, down to single-molecule resolution. Our long-term objective is to understand how the actin cytoskeleton interacts with subcellular processes (e.g. transcription) and systems (e.g. nucleus) to orchestrate cell shape change with “the right” kinetics, robust- ness and mechanical properties to achieve successful organismal outcomes. In the next five years, we will focus on three goals arising from our ongoing studies: Goal 1. Determine how gene expression regulates actin remod- eling – Gene expression instructs morphogenesis. Yet, we do not know how transcriptional dynamics inform actin remodeling. For cellularization, five genes that encode actin regulators must be transcribed. We will test a hypothesis that quantitative features of transcription of these genes underpin the global synchrony and uniformity of cellularization in embryos. Goal 2. Determine mechanisms of actomyosin contraction – Actomyosin contraction is essential to cell shape change, but its mechanism is controversial. During cellularization, actomyosin rings contract in back-to-back phases that are mechanistically distinct (Myosin-2 dependent versus independent). We will determine how actin binding proteins drive each mechanism. Goal 3. Determine how the actin cytoskeleton responds to environmental stress – Actin is increasingly recognized as a mediator of stress response. We re- cently identified a heat inducible Actin Stress Response (ASR) in embryos. We will test the hypothesis that ASR puts embryo viability at risk by altering homeostasis between free actin pools in the cytoplasm and nucleus. These goals build on each other so that we will understand how mechanisms before, during and after actin remodeling work together to determine outcomes for the embryo. Our efforts are facilitated by my lab’s proven ability to quantify phenotypes and relate events across scales and subcellular systems. The proteins and processes we study are conserved across organisms so our findings will be broadly relevant.

项目摘要/摘要 教科书告诉我们，肌动蛋白丝会赋予细胞形状，以及蛋白质驱动的“零件清单” 细胞改变形状时肌动蛋白的重塑。但是这个简单的讲述中缺少的是整体理解 关于上游基因表达和信号控制肌动蛋白重塑的方式，不同的蛋白如何一起起作用 重塑肌动蛋白，以及如何将下游细胞形状变化转化为及时可靠的有机外 来。因为基于肌动蛋白的故障可能源于重塑之前，之中和之后的事件，所以我们需要一个 综合理解以理解肌动蛋白在健康和疾病中的关键作用。 为了获得肌动蛋白的这种“全局”视图，我的实验室研究细胞化，第一个组织建造 果蝇胚胎中的事件。我们开发了这个简单的实验系统，以便我们可以研究肌动蛋白 重塑驱动细胞化的重塑，同时还将重塑与基因水平的上游事件相关联 表达和信号传导，以及下游结果，包括形态发育保真度和胚胎生存力。 我们的方法将果蝇遗传学和胚胎学与mRNA的定量活细胞成像结合在一起 和肌动蛋白调节蛋白，直至单分子分辨率。 我们的长期目标是了解肌动蛋白细胞骨架如何与亚细胞过程相互作用 （例如，转录）和系统（例如核），以“右”动力学来调整细胞形状，可靠 - NES和机械性能，以实现成功的有机结果。在接下来的五年中，我们将集中精力 在我们正在进行的研究中引起的三个目标：目标1。确定基因表达如何调节肌动蛋白的改造 - Eling - 基因表达指示形态发生。但是，我们不知道转录动态信息如何 肌动蛋白重塑。对于细胞化，必须转录编码肌动蛋白调节剂的五个基因。我们将测试 假设这些基因转录的定量特征是全局同步和均匀性的基础 胚胎中的细胞化。目标2。确定肌动蛋白收缩的机制 - 肌动蛋白收缩 对于细胞形状的变化至关重要，但其机制是有争议的。在细胞化期间，肌动球蛋白环 在机械上不同的背对背阶段（肌球蛋白2依赖与独立）收缩。我们 将确定肌动蛋白结合蛋白如何驱动每种机制。目标3。确定肌动蛋白细胞骨架如何 对环境压力的反应 - 肌动蛋白越来越被认为是压力反应的介体。是- 集中识别胚胎中的热诱导肌动蛋白应激反应（ASR）。我们将检验ASR的假设 通过改变细胞质和细胞核中游离肌动蛋白库之间的体内稳态来改变胚胎生存力。 这些目标相互建立，以便我们了解之前，之中和之后的机制 肌动蛋白重塑共同确定胚胎的结果。我们的努力是由我的实验室准备的 量化表型和跨尺度和亚细胞系统的事件的验证能力。蛋白质和 我们研究的过程在各种生物体之间是保守的，因此我们的发现将与众不同。