Mechanisms for building and remodeling microtubule arrays

项目摘要 对细胞内部组织的控制对所有生物体的形式和功能都是必不可少的。这种能力 主要依赖于称为细胞骨架的复杂的蛋白质细丝网络，它起到了脚手架的作用 结构，以在空间和时间上形成细胞内容的模式。与人造脚手架结构不同的是， 细胞骨架是高度动态的，能够改变其结构，以响应发育和 环境信号，使细胞能够适应不断变化的条件。因此，细胞骨架就像一个永远的- 改变结构“图”，我的研究项目的目标是了解这些图是如何 产生来执行构成生长、发育和生理基础的基本细胞活动。 我们的研究集中在创建、维护和重组的机制上 以拟南芥皮质微管阵列为实验材料的微管细胞骨架 易驾驭的系统。我们使用多学科方法，并受益于广泛的近距离网络 我们可以自由分享试剂和想法的合作者。这些优势使我们能够解决 以前关于细胞骨架结构和功能的棘手问题。在这里，我们将在我们最近的 重点关注四个主要目标的进展：目标1)确定具体调整的新监管机制的特点 Katanin切断微管的活性以揭示各种内外信号如何影响 通过卡塔宁组装和拆解不同的微管结构。目标2)阐明结构 决定MAP65微管交联蛋白功能多样性的动力学研究 进化如何选择特定的MAP65序列来实现特殊的功能，并使创建 操纵动植物体内微管功能的新工具。目标3)发现结构和 一类新的微管负端调节因子的作用机制了解TOG结构域， 它们通常与微管+末端跟踪蛋白相关，已被改变用途以识别 稳定微管负端。目标4)开发新的微流控芯片平台以分析 多组微管调节蛋白之间的复杂关系，以获得清晰完整的图像 同时进行的分子活动如何动态地构筑微管结构。总而言之，这些协同效应 项目将提供复杂微管结构内部工作机制的详细机械图景 并促进我们对它们在细胞生物学和疾病中的功能的理解。

Project Summary Control of the internal organization of cells is essential to the form and function of all organisms. This ability rests largely on an intricate protein filament network called the cytoskeleton which serves as a scaffolding structure to pattern cellular contents in space and time. Unlike human-made scaffolding structures, the cytoskeleton is highly dynamic and is able to change its configuration in response to developmental and environmental signals, allowing cells to adapt to changing conditions. Thus, the cytoskeleton is like an ever- changing structural “diagram”, and the goal of my research program is to understand how these diagrams are generated to execute essential cellular activities that underlie growth, development and physiology. Our research focuses on mechanisms for the creation, maintenance and restructuring of the microtubule cytoskeleton using the cortical microtubule array of Arabidopsis thaliana as an experimentally tractable system. We use a multidisciplinary approach and benefit from an extensive network of close collaborators with whom we freely share reagents and ideas. These advantages have allowed us to address previously intractable questions about cytoskeleton structure and function. Here, we will build on our recent progress to focus on four major goals: Goal 1) characterize new regulatory mechanisms that specifically tune the microtubule severing activity of katanin to uncover how various internal and external signals influence the assembly and disassembly of diverse microtubule structures through katanin. Goal 2) elucidate the structural dynamics that determine the functional diversity of MAP65 microtubule crosslinking proteins to gain insight into how evolution selected particular MAP65 sequences for specialized functions and to enable the creation of new tools to manipulate microtubule function in plants and animals. Goal 3) uncover the structure and mechanism of action of a new class of microtubule minus-end regulators to understand how TOG domains, which are typically associated with microtubule plus-end tracking proteins, have been repurposed to recognize and stabilize microtubule minus-ends. Goal 4) develop a new microfluidics chip platform to analyze the complex relationships between sets of microtubule regulatory proteins to obtain a clear and integrated picture of how concurrent molecular activities dynamically pattern microtubule structures. Together, these synergistic projects will provide a mechanistically detailed picture of the inner workings of complex microtubule structures and advance our understanding of their functions in cell biology and disease.