Control of development by ubiquitin and endocytosis

描述(申请人提供)：提出的研究的总体目标是 了解泛素化和内吞作用如何调节特定细胞 动物发育过程中的沟通途径。使用以下组合 遗传、分子和生化技术，一种独特的机制 在动物发育过程中细胞通讯的调节将是 调查过了。 果蝇复眼构图所必需的细胞信号通路 已经确定；信号细胞需要一个 去泛素酶称为脂肪小面(FAF)。FAF在这些方面的作用 细胞将从一种名为液体小面的蛋白质中切割泛素(Ub)链 (Lqf)。当Ub链以Lqf为降级目标时，Faf活动增加了 Lqf在信令细胞中的水平。FAF是唯一一个 一种从特定蛋白质中移除Ub链的去泛素酶 泛素化的功能类似于磷酸酶的功能 关于磷酸化。此外，Lqf是果蝇Eepsin的同源物， 脊椎动物内吞蛋白，其功能鲜为人知。因此，一个 内吞蛋白是通过Ub调节细胞通讯的靶标 对细胞决定至关重要的途径。 首先，果蝇分子遗传学将被用来识别其他 果蝇眼睛中基本的Faf/Lqf通路的组成。第二， Faf在果蝇发育中的其他作用底物将是 已确认身份。第三，Lqf蛋白与其相互作用所需的部分 FAF及其其他功能将本地化。第四，基因筛查 建议研究Lqf在内吞作用和其他 潜在的进程。最后，第二个果蝇epsin基因D-epsin2将被 分析；将研究D-epsin2的结构和功能。 由于Faf和Lqf有人类同源基因，这里阐明的途径如下 对动物细胞来说是通用的。此外，由于Ub介导的蛋白质降解和 内吞作用对许多细胞功能、几种人类疾病都很重要 基因，包括癌基因和与帕金森病有关的基因？S和 阿尔茨海默病？S，编码这两条途径的蛋白质。

DESCRIPTION (provided by applicant): The broad goal of the research proposed is to understand how ubiquitination and endocytosis regulate particular cell communication pathways during animal development. Using a combination of genetic, molecular and biochemical techniques, a unique mechanism for the regulation of cell communication during animal development will be investigated. A cell signaling pathway essential for patterning the Drosophila compound eye has been identified; the signaling cells require the activity of a deubiquitinating enzyme called Fat facets (Faf). The function of Faf in these cells is to cleave a ubiquitin (Ub) chain from a protein called Liquid facets (Lqf). As the Ub chain targets Lqf for degradation, Faf activity increases the level of Lqf in the signaling cells. Faf is the only example of a deubiquitinating enzyme that removes a Ub chain from a specific protein, a function with respect to ubiquitination similar to that of a phosphatase with respect to phosphorylation. Moreover, Lqf is a Drosophila homolog of epsin, a vertebrate endocytic protein whose function is poorly understood. Thus, an endocytic protein is the target for regulating, via Ub, a cell communication pathway critical to cell determination. First, Drosophila molecular genetics will be used to identify additional components of the essential Faf/Lqf pathway in the Drosophila eye. Second, the substrates of Faf in its other roles in Drosophila development will be identified. Third, portions of Lqf protein required for its interaction with Faf, and for its other functions, will be localized. Fourth, a genetic screen is proposed to investigate the function of Lqf in endocytosis and other potential processes. Finally, a second Drosophila epsin gene, D-epsin2, will be analyzed; the structure and function of D-epsin2 will be investigated. As Faf and Lqf have human homologs, the pathways elucidated here will be universal for animal cells. Moreover, as Ub-mediated protein degradation and endocytosis are important for many cellular functions, several human disease genes, including oncogenes and also genes implicated in Parkinson?s and Alzheimer?s, encode proteins in these two pathways.