Roles of Retromer Complex in Development

逆转录酶复合物在发育中的作用

• 批准号: 8035474
• 负责人: XINHUA LIN
• 金额: $ 28.75万
• 依托单位: CINCINNATI CHILDRENS HOSP MED CTR
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8035474
• 关键词: Binding; Biochemical; Biological; Blood; Caenorhabditis elegans; Cell Culture Techniques; Cell physiology; Cells; Cellular biology; Complex; Data; Defect; Development; Developmental Process; Dorsal; Drosophila genus; Embryo; Embryonic Development; Endocytosis; Endosomes; Epithelial Cells; Epithelium; Fat Body; Genetic; Goals; Golgi Apparatus; Integral Membrane Protein; Larva; Lysosomes; Malignant Neoplasms; Mammalian Cell; Mediating; Membrane; Modeling; Molecular; Outcome; Pathologic Processes; Process; Proteins; Recycling; Regulation; Role; Signal Pathway; Signal Transduction; Testing; Tissues; Ubiquitination; Vesicle; Work; Yeasts; base; human IGF2R protein; human disease; insight; mutant; notch protein; novel; protein complex; protein transport; public health relevance; retrograde transport; sorting nexins; trafficking; trans-Golgi Network

DESCRIPTION (provided by applicant): The long-term goal of this project is to understand the molecular mechanisms by which retromer controls cellular processes during development. Retromer is an evolutionarily conserved multi-subunit complex, consisting of two complexes, the cargo recognition Vps26-Vps29- Vps35 heterotrimer and a membrane-targeting heterodimer or homodimer. Early studies in yeast and mammalian cell culture have demonstrated its roles in mediating endosome-Golgi trafficking of several proteins including mammalian cation-independent mannose-6-phosphate receptor. However, the roles of retromer complex in development have not been examined until recently. Our recent studies have uncovered an essential role of retromer complex in Wnt secretion. We showed that retromer is involved in endosome-to-Golgi transport of Wntless (Wls), a seven-pass transmembrane protein required for Wnt secretion. In the absence of retromer activity, Wls is unstable and is degraded, thereby causing Wnt secretion defects. Importantly, while retromer is not involved in many other developmental signaling pathways, we found that retromer is crucial for other two essential developmental processes including (1) the apicobasal polarity of epithelium during Drosophila embryogenesis and (2) hematopoeisis during larval development. Our preliminary studies have demonstrated that retromer regulates the trafficking of Crumbs (crb) to control the apicobasal polarity of epithelium, while it is involved in regulating Toll/Dorsal signaling pathway to control hematopoeisis. Thus, our studies have uncovered three essential roles of the retromer complex in development. In this application, we will further investigate the roles of retromer in Wnt secretion, in the apicobasal polarity control and in Toll/dorsal signaling pathway. In Aim1, we will examine the roles of ubiquitination and retromer in regulating Wls stability and recycling. In Aim2, we will examine whether retromer controls epithelium polarity by regulating Crumb trafficking and stability. In Aim3, we will determine the mechanism by which retromer regulates Toll trafficking and signaling. Together, our proposed studies will provide new insights into the mechanisms by which retromer regulates Wnt secretion, epithelium polarity and Toll/dorsal signaling during development. PUBLIC HEALTH RELEVANCE: Retromer controls Wnt and Toll signaling pathways as well as epithelium polarity. These signaling pathways and cell biology processes are essential for embryonic development. Defects in Wnt and Toll signaling pathways as well as epithelium polarity are associated with many human diseases including cancers. The outcomes of this application will help understanding related human disease processes.

描述（由申请人提供）：该项目的长期目标是了解逆转录酶在发育过程中控制细胞过程的分子机制。 Retromer是一种进化上保守的多亚基复合物，由两个复合物组成，即货物识别Vps26-Vps29-Vps35异三聚体和膜靶向异二聚体或同二聚体。酵母和哺乳动物细胞培养的早期研究已证明其在介导多种蛋白质（包括哺乳动物阳离子非依赖性甘露糖-6-磷酸受体）的内体-高尔基体运输中的作用。然而，直到最近才研究了逆转录酶复合物在发育中的作用。我们最近的研究发现了逆转录酶复合物在 Wnt 分泌中的重要作用。我们发现，retromer 参与 Wntless (Wls) 的内体到高尔基体的转运，Wntless 是 Wnt 分泌所需的七次跨膜蛋白。在缺乏逆转录酶活性的情况下，Wls不稳定并被降解，从而导致Wnt分泌缺陷。重要的是，虽然逆转录酶不参与许多其他发育信号通路，但我们发现逆转录酶对于其他两个重要的发育过程至关重要，包括（1）果蝇胚胎发生过程中上皮的顶端基底极性和（2）幼虫发育过程中的造血作用。我们的初步研究表明，Retromer通过调节Crumbs（crb）的运输来控制上皮的顶端基底极性，同时参与调节Toll/Dorsal信号通路来控制造血。因此，我们的研究揭示了逆转录酶复合物在发育中的三个重要作用。在本申请中，我们将进一步研究retromer在Wnt分泌、apicobasal极性控制和Toll/dorsal信号通路中的作用。在 Aim1 中，我们将研究泛素化和逆转录酶在调节 Wls 稳定性和回收中的作用。在 Aim2 中，我们将研究逆转录酶是否通过调节 Crumb 运输和稳定性来控制上皮极性。在 Aim3 中，我们将确定逆转录酶调节 Toll 传输和信号传导的机制。总之，我们提出的研究将为逆转录酶在发育过程中调节 Wnt 分泌、上皮极性和 Toll/dorsal 信号传导的机制提供新的见解。 公共健康相关性：Retromer 控制 Wnt 和 Toll 信号通路以及上皮极性。这些信号通路和细胞生物学过程对于胚胎发育至关重要。 Wnt 和 Toll 信号通路以及上皮极性的缺陷与包括癌症在内的许多人类疾病有关。该应用的结果将有助于了解相关的人类疾病过程。