Shaping Cells Using Modular Actin Filament Bundles

细胞形状是细胞功能的关键组成部分。 极化肌动蛋白丝的交联束在真核细胞中很常见，并为创造和维持细胞形状提供了支架。 果蝇刚毛细胞是研究肌动蛋白束组装和细胞形状控制的一个很好的模型系统，因为它们含有非常大的肌动蛋白束，并代表了一个非常易于处理的遗传操作和活细胞成像系统。 这些捆包是工程奇迹。 它们可以长到超过400微米长，从500到25根细丝逐渐变细20倍-从基部到尖端。 令人惊讶的是，这些结构是通过将数百个2微米的模块嫁接在一起而构建的，这些模块首先伸长，然后通过添加细丝来扩展。 束组装是一个出乎意料的动态过程，本项目旨在确定肌动蛋白丝的合成和周转如何有助于束组装。 分子和遗传工具将被用来修改肌动蛋白束组装和共聚焦和电子显微镜技术用于评估生物学后果的时间和高分辨率。 从这项研究的结果应该告诉我们，在许多细胞，如微绒毛上的吸附上皮细胞在肠道和肾脏和内耳毛细胞上的静纤毛专门膜突起的建设。 该项目还将把本科生纳入以研究为导向的团队方法。

Cell shape is a critical component of cell function. Cross-linked bundles of polarized actin filaments are common in eukaryotic cells and provide the scaffolding for creating and maintaining cell shape. Drosophila bristle cells are an excellent model system to investigate actin bundle assembly and cell shape control because they contain extraordinary large actin bundles and represent an extremely tractable system for genetic manipulation and live cell imaging. These bundles are an engineering marvel. They can grow to over 400 microns in length and taper 20-fold from 500 to 25 filaments - from base to tip. Amazingly, these structures are built by grafting together hundreds of 2-micron modules that first elongate and then thicken by filament addition. Bundle assembly is an unexpectedly dynamic process, and this project is aimed at determining how actin filament synthesis and turnover contributes to bundle assembly. Molecular and genetic tools will be employed to modify actin bundle assembly and confocal and electron microscopic techniques used to evaluate the biological consequences temporally and at high resolution. Results from this research should inform us about the construction of specialized membrane protrusions in many cells such as the microvilli on the adsorptive epithelial cells in the gut and the kidney and the stereocilia on the hair cells in the inner ear. This project will also incorporate undergraduates in a research-oriented team approach.