Mechanisms of microridge protrusion morphogenesis on mucosal epithelial cells

粘膜上皮细胞微嵴突起形态发生机制

基本信息

批准号：
10330685
负责人：
Alvaro Sagasti
金额：
$ 38.18万
依托单位：
UNIVERSITY OF CALIFORNIA LOS ANGELES
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-01-01 至 2026-12-31
项目状态：
未结题

项目摘要

PROJECT SUMMARY Actin-based protrusions endow cells with a vast variety of forms. Cells on the surface of mucosal epithelial tissues, such as the cornea and mouth, often project elongated, wrinkle-like protrusions called microridges, which are arranged on apical surfaces in maze-like patterns. Microridges help these cells retain mucus, thus protecting vulnerable epithelial tissues from infection, abrasion and drying out. Until recently, almost nothing was known about microridge morphogenesis. Since microridge morphologies are distinct from those of better- studied protrusions, studying them could reveal fundamental new principles of protrusion morphogenesis. In recent years, the Sagasti lab established larval zebrafish skin cells as a model for studying microridge morphogenesis. This model enables powerful molecular manipulations and live imaging of morphogenesis. The Sagasti lab’s initial studies revealed several new discoveries, including: 1) The dissection of microridge morphogenesis into four molecularly separable steps, 2) the discovery that myosin contraction in the apical cortex regulates surface tension to permit microridge formation, 3) the identification of Plakin cytolinkers as master regulators of microridge length, 4) the discovery that keratin filaments are integral components of microridges required for their stability and elongation (the first example of intermediate filaments directly contributing to protrusion morphogenesis), and 5) the discovery that cortical myosin minifilaments orchestrate an unusual microridge fission/fusion rearrangement process that facilitates the formation of regular, periodic microridge arrangements on cell surfaces. Collectively, these discoveries have broad implications for how cortical myosin, cytolinkers, and intermediate filaments contribute to protrusion morphogenesis. Building on these achievements and new preliminary data, the Sagasti lab will pursue two future lines of research. First, since cortical contractility creates the biomechanical conditions enabling microridge morphogenesis, they will investigate how cross-linking proteins and cell junctions temporally and spatially tune cortical contractility to promote microridge formation and patterning. Since cortical contractility controls many cellular processes, these experiments will reveal regulatory mechanisms with wide relevance in cell biology. Second, since Plakin cytolinkers are central regulators of microridge initiation and elongation, they will investigate how the structure of Plakins relate to their functional roles in microridge morphogenesis, and use Plakin proteins as handles for identifying new regulatory components of the cytoskeletal scaffold that creates microridge protrusions.

项目摘要基于肌动蛋白的突起具有各种形式。粘膜上皮表面的细胞组织，例如角膜和嘴，通常会伸长的细长，皱纹样蛋白，称为Microretges，这些以迷宫状模式排列在顶部表面上。微型树木帮助这些细胞保留粘液，因此保护脆弱的上皮组织免受感染，磨损和干燥。直到最近，几乎没有由于micridge形态与更好的形态不同研究它们的突起，研究它们可以揭示突出形态发生的新原理。近年来，萨加斯蒂实验室建立了幼虫斑马鱼皮细胞，作为研究Microdide的模型形态发生。该模型可实现强大的分子操作和形态发生的实时成像。萨加斯蒂实验室的初步研究揭示了几个新发现，包括：1）Microidgide的解剖形态发生分为四个分子分开的步骤，2）发现根尖的肌球蛋白收缩皮层调节表面张力以允许Micridge形成，3）识别Plakin细胞链接剂为 Micridge长度的主调节器，4）发现角蛋白细丝是不可或缺的组成部分的发现其稳定性和伸长所需的微型树木（直接中间丝的第一个例子有助于突出形态发生），以及5）发现皮质肌球蛋白微型纤维编排的发现一个不寻常的Microids裂变/融合重排过程，可促进常规，周期性的形成细胞表面上的Microids排列。总的来说，这些发现对皮质肌球蛋白，细胞链接和中间丝有助于突出形态发生。在这些成就和新的初步数据的基础上，Sagasti Lab将在以后的两条线上遵循研究。首先，由于皮质收缩力创造了生物力学条件，使Microridge能够形态发生，他们将研究如何临时和空间调整交联蛋白和细胞连接皮质收缩能促进Microidge的形成和图案。由于皮质收缩能控制着许多细胞过程，这些实验将揭示在细胞生物学中相关性广泛的调节机制。其次，由于普拉金细胞链接器是Micridge Initiative and Retongation的中心调节剂，因此它们将研究普拉金的结构如何与它们在微岛形态发生中的功能作用相关，并使用 plakin蛋白作为识别创建细胞骨骼支架的新调节成分的手柄 Micridge蛋白。