Developmental regulation of epithelial polarization by pre-mRNA splicing

mRNA前体剪接对上皮极化的发育调节

基本信息

批准号：
10583675
负责人：
Michel Bagnat
金额：
$ 46.19万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-02-01 至 2026-11-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10583675
关键词：
Affect Amino Acids Apical Automobile Driving Biological Cell Polarity Clathrin Adaptors Complex Data Defect Degradation Pathway Dependence Development Diarrhea Dietary Proteins Digestion Disease Endocytosis Endosomes Enterocytes Epithelial Cells Epithelium Food Gastrointestinal tract structure Genes Genetic Genetic Screening Goals Golgi Apparatus Homeostasis Impairment Intestinal Absorption Intestines Introns Ion Channel Lipids Lysosomes Malabsorption Syndromes Malignant Neoplasms Membrane Proteins Membrane Transport Proteins Minor Modeling Morphology Mucins Mutation NGFR Protein Nutrient Pathway interactions Physiological Physiology Play Polysaccharides Process Protein Glycosylation Protein Sortings Proteins Proton-Translocating ATPases RNA Splicing Regulation Role Sorting Surface System Systemic disease Testing Transcript Transmembrane Transport Vacuole Visual Zebrafish absorption apical membrane basolateral membrane fluorescence imaging forward genetics glycosylation improved in vivo intestinal epithelium intestinal maturation intrinsic factor-cobalamin receptor mRNA Precursor mutant nutrient absorption organ growth particle public health relevance receptor segregation sugar superresolution microscopy trafficking transcriptional coactivator p75 transcriptome sequencing uptake vacuolar H+-ATPase

项目摘要

Abstract The apical membrane of epithelial cells in the intestine play critical roles in physiology and homeostasis. Many specialized functions of intestinal epithelial cells, such as nutrient absorption, depend on faithfully sorting proteins to the apical membrane during biosynthetic delivery. However, the cellular mechanisms driving apical membrane protein sorting and how it matures during development are poorly defined. Also unknown is what controls the onset of apical endocytosis in Lysosome Rich Enterocytes (LREs). To discover mechanisms of apical membrane polarization in vivo, we performed a forward genetics screen for factors required for sorting of a model apical cargo (O-glycan-GFP, Og-GFP) in the zebrafish intestine. We isolated distinct classes of mutants affecting apical Og-GFP sorting. Our preliminary data has uncovered a pH-dependent mechanism for sorting membrane proteins in subapical endosomes either to the degradative pathway or to the apical membrane. We also discovered a role for regulated pre-mRNA intron splicing in activating apical membrane transport pathways crucial for polarized protein delivery in enterocytes and for apical endocytosis in LREs of the developing intestine. Our studies will uncover genetic and cellular mechanisms crucial for the maturation of a fully polarized and physiologically active epithelium in the vertebrate gut.

抽象的肠道上皮细胞顶膜在生理和体内平衡中发挥着关键作用。许多肠上皮细胞的特殊功能，例如营养吸收，取决于蛋白质的忠实分类在生物合成过程中到达顶膜。然而，驱动顶膜的细胞机制蛋白质分类及其在发育过程中如何成熟尚不清楚。还未知是什么控制着富含溶酶体的肠细胞 (LRE) 开始发生顶端内吞作用。发现顶膜的机制为了体内极化，我们对模型顶端排序所需的因素进行了正向遗传学筛选斑马鱼肠道中的货物（O-聚糖-GFP、Og-GFP）。我们分离出了影响顶端的不同类别的突变体 Og-GFP 排序。我们的初步数据揭示了一种 pH 依赖性膜蛋白分选机制在顶端下内体中，要么进入降解途径，要么进入顶膜。我们还发现了一个角色用于调节前体 mRNA 内含子剪接，激活对极化至关重要的顶膜转运途径肠细胞中的蛋白质递送以及发育中肠道的 LRE 中的顶端内吞作用。我们的研究将揭示对于完全极化和生理活性的成熟至关重要的遗传和细胞机制脊椎动物肠道中的上皮。