Building and shaping narrow epithelial tubes in C. elegans

项目摘要 我的实验室研究基因和细胞生物学机制， 保护上皮管，重点是非常狭窄的单细胞管和顶端 细胞外基质（aECM）。两者都是与人类疾病有关的主题， 毛细血管和其他狭窄的管道，但在大多数动物模型中研究具有挑战性 这是因为难以对相关结构和分子成像。线虫C. 通过对活体动物进行成像， 在亚细胞分辨率，结合强大的遗传方法，以确定相关的 基因和途径。我们最近的工作表明，单细胞管的形状是：（i） 依赖于融合蛋白（AFF-1）的细胞内膜运输事件更好地 已知其在细胞-细胞融合中的作用;和（ii）新发现的aECM类型， 位于角质层之前，含有类似于在某些组织中或附近发现的蛋白质。 哺乳动物ECM（例如具有富含亮氨酸的重复序列、纤溶酶原、透明质酸， 粘蛋白和/或巢蛋白结构域）。这种aECM也依赖于假定的脂质转运蛋白， 脂质运载蛋白、清道夫受体B（SCARB）和Patched相关家族。我们的研究 未来五年的计划将跟进这些进展，以更好地了解 参与构建单细胞管和结构的特定运输事件， aECM的功能。例如，我们将进一步测试AFF-1介导的模型， 内吞分裂，使膜从基底表面穿梭到顶端表面， 延长管腔，我们将确定AFF-1结构域和参与此过程的合作伙伴 切断函数我们将研究特定的糖蛋白如何运输和组装 在aECM中，转运蛋白家族如何调节适当的aECM脂质含量， 以及单个aECM组件如何影响不同尺寸的 在有机体中。

Project Summary My laboratory studies genes and cell biological mechanisms that form, shape and protect epithelial tubes, with a focus on very narrow unicellular tubes and apical extracellular matrix (aECM). Both are topics relevant to human diseases involving capillaries and other narrow tubes, but are challenging to study in most animal models due to difficulties in imaging the relevant structures and molecules. The nematode C. elegans allows us to circumvent these challenges by permitting imaging of live animals at sub-cellular resolution, combined with powerful genetic approaches to identify relevant genes and pathways. Our recent work showed that a unicellular tube is shaped by: (i) intracellular membrane trafficking events that rely on a fusogen protein (AFF-1) better known for its roles in cell-cell fusion; and (ii) a newly discovered type of aECM that precedes the cuticle and contains proteins similar to those found in or near some mammalian ECMs (e.g. those with leucine-rich repeat, plasminogen, zona pellucida, mucin and/or nidogen domains). This aECM also relies on putative lipid transporters of the lipocalin, scavenger receptor B (SCARB) and Patched-related families. Our research program in the next five years will follow up on these advances to better understand the specific trafficking events involved in building unicellular tubes and the structure and function of the aECM. For example, we will further test the model that AFF-1 mediates endocytic scission to allow membrane to be shuttled from basal to apical surfaces to extend the tube lumen, and we will identify AFF-1 domains and partners involved in this scission function. We will investigate how specific glycoproteins traffic to and assemble within the aECM, how proper aECM lipid content is regulated by transporter families, and how individual aECM components affect the shape and integrity of differently-sized tubes in the organism.