Trio/CARMIL Regulation of Epithelial Cell Rearrangement

Trio/CARMIL 对上皮细胞重排的调节

• 批准号: 9903409
• 负责人: Jeffrey D Hardin
• 金额: $ 30.09万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-05-01 至 2022-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9903409
• 关键词: Actins; Alleles; Area; Binding; Biochemical; Biological Models; Buffers; Caenorhabditis elegans; Cells; Congenital Abnormality; Dorsal; Embryo; Embryonic Development; Embryonic Structures; Epidermis; Epithelial Cells; Event; Family; Future; Genetic; Guanine Nucleotide Exchange Factors; Human; Human Development; Intercalated Cell; Invaded; Modeling; Movement; Multiprotein Complexes; Muscle Cells; Myosin Type I; Neuraxis; Pathway interactions; Phylogenetic Analysis; Positioning Attribute; Process; Proteins; Regulation; Role; Screening procedure; Structure; Technology; Testing; Tissues; Work; actin capping protein; appendage; cancer cell; directional cell; experimental study; gain of function; gastrulation; genetic approach; genome sequencing; human disease; in vivo; intercalation; novel; polymerization; rac GTP-Binding Proteins; recruit; rho; whole genome

Project Summary The directed rearrangement of epithelial cells is crucial during human development, including the events of gastrulation and neurulation. How basolateral protrusive activity contributes to this process is poorly understood. Dorsal intercalation in the epidermis of the C. elegans embryo is an outstanding model system for examining basolateral events during epithelial cell rearrangement at the level of single cells. We have shown that dorsal intercalation relies on a phylogenetically conserved Rac/RhoG cassette activated by the Rho family guanine nucleotide exchange factor (GEF), UNC-73/Trio, and is negatively regulated by the highly conserved actin capping protein regulator, CRML-1/CARMIL (capping protein-, Arp2/3- and myosin I-linker protein). This new proposal will investigate how this conserved Rac/RhoG cassette regulates directed cell rearrangement by performing experiments in four areas: (1) We will use embryological and structure-function approaches to determine how CRML- 1/CARMIL localizes to the rear of intercalating cells; (2) We will use biochemical and in vivo rescue experiments to determine whether CRML-1 negatively regulates the Trio/Rac/RhoG pathway via direct binding or indirectly through its effects on capping protein recruitment; (3) We will determine whether a Slit/Robo/srGAP cassette regulates Rac via localized repulsion or as a “cell contact buffer”; and (4) We will determine how additional components regulate the Trio/Rac/RhoG pathway using candidate screens and forward genetic approaches. As a result of these studies, we will elucidate a novel pathway regulating cell intercalation via basolateral protrusive activity, a widespread process with implications for understanding major birth defects and normal human embryogenesis.

项目摘要 上皮细胞的定向重排在人类发育过程中至关重要，包括 原肠胚形成和神经胚形成。基底外侧神经元的活动如何对此做出贡献 过程不太清楚。背插在表皮的C。线虫胚胎是 一个杰出的模型系统，用于检查上皮细胞生长过程中的基底侧事件， 在单细胞水平上的重排。我们已经证明，背插层依赖于一个 由Rho家族鸟嘌呤核苷酸激活的遗传上保守的Rac/RhoG盒 交换因子（GEF），α-73/Trio，并由高度保守的肌动蛋白负调控 加帽蛋白调节剂，CRML-1/CARMIL（加帽蛋白-，Arp 2/3-和肌球蛋白I-连接体 蛋白质）。 这项新的提议将研究这种保守的Rac/RhoG盒如何调节定向的 通过在四个方面进行实验来进行细胞重排： (1)我们将使用胚胎学和结构-功能方法来确定CRML- 1/CARMIL定位于闰细胞后部; (2)我们将使用生物化学和体内拯救实验来确定CRML-1是否 通过直接结合或间接通过其抑制剂，负调节Trio/Rac/RhoG途径。 对加帽蛋白募集的影响; (3)我们将确定Slit/Robo/srGAP盒是否通过局部排斥调节Rac 或作为“细胞接触缓冲液”;以及 (4)我们将确定其他成分如何调节Trio/Rac/RhoG通路， 候选人筛选和前瞻性遗传方法。 作为这些研究的结果，我们将阐明一个新的途径调节细胞嵌入， 基底外侧活动，这是一个广泛的过程，对理解主要 出生缺陷和正常的人类胚胎发育。