The role of Dzip1L in ciliogenesis and Hedgehog signaling

Dzip1L 在纤毛发生和 Hedgehog 信号传导中的作用

基本信息

批准号：
9244039
负责人：
BAOLIN WANG
金额：
$ 35.6万
依托单位：
WEILL MEDICAL COLL OF CORNELL UNIV
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-04-01 至 2019-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9244039
关键词：
Activator Appliances Affect Alleles Apical Biological Birth Brain C-terminal Cell membrane Cell surface Cells Centrioles Centrosome Cilia Defect Disease Docking Embryo Environment Epithelial Cells Erinaceidae Exhibits Fibroblasts Functional disorder Gene Mutation Genes Genetic Genetic study Golgi Apparatus Growth Human Iguanas Immunofluorescence Immunologic Knockout Mice Length Light Limb Bud Limb structure Mesenchymal Microtubules Midbrain structure Molecular Morphology Mothers Mus Mutant Strains Mice Mutate Mutation Neural tube Neuroepithelial Neuroepithelial Cells Organelles Pathway interactions Pattern Phenotype Polydactyly Process Prosencephalon Proteins Regulation Role Sensory Signal Transduction Signaling Molecule Smooth Muscle Myocytes Stretching Structure Time Tissues Transmission Electron Microscopy Vesicle Western Blotting Zebrafish base cilium biogenesis drug development extracellular human disease insight kinetosome mutant progenitor public health relevance smoothened signaling pathway therapeutic target transcription factor

项目摘要

DESCRIPTION (provided by applicant): The primary cilium is a solitary microtubule-based organelle that protrudes from the cell surface and is found on most vertebrate cells. Primary cilia originate in the mother centriole of the centrosome and are elongated and maintained by intraflagellar transport (IFT). Previous transmission electron microscopy (TEM) studies defined two different ciliogenesis pathways for primary cilia. In epithelial cells, the mother centriole appears to dock directly at the apical plasma membrane; from there, the axoneme grows out toward the extracellular environment. This is called the extracellular pathway. In contrast, in fibroblasts and smooth muscle cells, the cilium appears to first grow within the cell body, upon docking of the mother centriole to a Golgi-derived primary ciliary vesicle. The growth of the axoneme takes place within this vesicle. Fusion of this vesicle with the plasma membrane finally allows the cilium to access the extracellular environment. This is called the intracellular pathway. Thus far, nothing is known about how these two pathways are differentially regulated at the molecular levels. Ciliary dysfunction disrupts Hedgehog (Hh) signaling by affecting the activity of the Gli2 and Gli3 transcription factors, two primary regulators of Hh signaling. Most known ciliary gene mutations identified thus far result in failed Gli2 activation and decreased Gli3 repressor levels, but the underlying molecular mechanisms remain poorly understood. We recently mutated the mouse Dzip1L gene, which encodes a centriolar protein. Dzip1L mutant mice exhibit polydactyly and an enlarged forebrain and midbrain. Loss of Dzip1L results in reduced Gli3 repressor activity but does not affect Gli2 activation. Surprisingly, although cilia ae normal in neuroepithelial cells of the Dzip1L mutant brain, there is a pronounced paucity of cilia in mutant limb bud mesenchymal cells and embryonic fibroblasts. Thus, Dzip1L is the first known cilia-related protein that specifically regulates ciliogenesis in fibroblasts, but not epitheial cells, and affects only Gli3 processing but not Gli2 activation. Our objective is to understand how Dzip1L mutation affects Gli3 processing but not Gli2 activation and how Dzip1L differentially regulates the two ciliogenesis pathways using genetic, molecular, and cell biological approaches.

描述（由适用提供）：主要的纤毛是一种固体微管细胞器，从细胞表面突出，在大多数脊椎动物细胞上发现。原发性纤毛起源于中心体的母亲中心，并由flagllar内运输（IFT）伸长和维护。先前的透射电子显微镜（TEM）研究定义了原发性纤毛的两种不同的纤毛发生途径。在上皮细胞中，母亲中心似乎直接停靠在顶端质膜上。从那里，轴突朝着细胞外环境生长。这称为细胞外途径。相比之下，在成纤维细胞和平滑肌细胞中，纤毛在将母中心对接到高尔基体衍生的原发性纤毛囊泡后，首先在细胞体内生长。轴突的生长发生在该囊泡中。该囊泡与质膜的融合最终使纤毛进入细胞外环境。这称为细胞内途径。这两个途径在分子水平上如何不同地调节这两种途径。睫状功能障碍通过影响GLI2和GLI3转录因子的活性（HH信号的两个主要调节剂）来破坏刺猬（HH）信号传导。迄今为止确定的最著名的睫状基因突变导致GLI2激活失败并改善了GLI3复制剂水平，但是潜在的分子机制仍然了解不足。我们最近突变了编码中心蛋白的小鼠DZIP1L基因。 DZIP1L突变小鼠多态度和肿大的前脑和中脑暴露。 DZIP1L的丢失导致GLI3复制器活性降低，但不会影响GLI2激活。令人惊讶的是，尽管DZIP1L突变体大脑的神经上皮细胞中的纤毛AE正常，但在突变体肢体芽中充质细胞和胚胎成纤维细胞中，纤毛的纤毛很明显。这是DZIP1L是第一个已知的纤毛相关蛋白，它专门调节成纤维细胞中的纤维生成，但不影响上皮细胞，仅影响GLI3处理，但不影响GLI2激活。我们的目标是了解DZIP1L突变如何影响GLI3处理，而不是GLI2激活，以及DZIP1L如何使用遗传，分子和细胞生物学方法来不同地调节两种纤毛生成途径。