A combined in vitro and in vivo study of the assembly mechanism of actin bundles in Drosophila bristles.

果蝇刚毛中肌动蛋白束组装机制的体外和体内联合研究。

• 批准号: 388532375
• 负责人: Professor Dr. Andreas Bausch
• 金额: --
• 依托单位: Lehrstuhl für Zellbiophysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/388532375?language=en
• 关键词: combined; vitro; vivo; study; assembly

Parallel actin bundles are composed of tightly packed filaments that all have the same polarity and are crosslinked by an actin-bundling protein and constitute a key component of eukaryotic cytoskeleton structures. Their function is to reinforce the cell against mechanical deformation and to allow localized force generation. One prominent actin bundle organization is found in Drosophila bristle cells. The bristle actin bundles are membrane-bound, triangular-shaped, and are organized into modules along their length. They are evenly spaced around the outer perimeter of the bristle, extending from the base of the bristle to its tip with well-defined spaces between modules. The formation of bristle actin bundles has already revealed a fascinating machinery of the growth process. However, the molecular mechanism determining and controlling the length and the shape of bristle actin bundles is still unknown. In this proposal we plan an inter-disciplinary study to identify the mechanism of Drosophila bristle formation by combining in vivo and in vitro experiments. We will identify the essential genes that are part of the bristle actin bundle machinery and use high-resolution light microscopy using transgenic flies, to reveal the growth rate limiting steps. Our hypothesis is that an intricate interplay between actin nucleation, crosslinking and depolymerization proteins, set the observed actin bundles length. To test this mechanism, an in vitro system of actin bundle formation will be developed. We will test how the triangular shape of the bundles depends on the longitudinal association of spontaneously nucleated filaments in the cytosol. Both in vivo as in in vitro experiments will be used to pin down the mechanism of the lateral growth and geometry of the bristles. As it is believed that common mechanisms are responsible for control of bundle shapes in a variety of systems, such as microvilli or stereocilia, the results of this study will affect our understanding well beyond the formation of bristles bundles.

平行肌动蛋白束由紧密排列的细丝组成，这些细丝都具有相同的极性，并由肌动蛋白束蛋白交联，构成真核细胞骨架结构的关键组成部分。它们的功能是加强细胞抵抗机械变形，并允许局部力的产生。在果蝇刚毛细胞中发现了一个突出的肌动蛋白束组织。刚毛肌动蛋白束是膜结合的，三角形的，并组织成模块沿着其长度。它们围绕刷毛的外周均匀地间隔开，从刷毛的基部延伸到其尖端，在模块之间具有明确限定的空间。刚毛肌动蛋白束的形成已经揭示了生长过程中一种迷人的机制。然而，决定和控制刚毛肌动蛋白束的长度和形状的分子机制仍然是未知的。在这个提议中，我们计划进行一项跨学科的研究，通过结合体内和体外实验来确定果蝇刚毛形成的机制。我们将确定的刚毛肌动蛋白束机械的一部分，并使用高分辨率光学显微镜转基因苍蝇，揭示生长速度限制步骤的必要基因。我们的假设是，肌动蛋白成核，交联和解聚蛋白之间的复杂的相互作用，设置所观察到的肌动蛋白束的长度。为了测试这种机制，将开发一种体外肌动蛋白束形成系统。 我们将测试如何三角形形状的束取决于纵向协会的自发核丝在胞质溶胶。无论是在体内，在体外实验将被用来钉下来的横向生长和几何形状的刷毛的机制。由于人们认为，共同的机制是负责控制束的形状在各种系统，如微绒毛或静纤毛，本研究的结果将影响我们的理解远远超出了刷毛束的形成。