Analysis of the Drosophila Gene Rhomboid

9318242 Bier本建议的目的是了解菱形(Rho)基因的功能，该基因在几个不同的发育事件中是必需的，包括：果蝇胚胎的早期背腹模式形成，胚胎感觉器官的形成，以及成年翅膀静脉的形成。Rho是形成这些不同结构所需的几个基因(称为腹侧组基因)之一。其他腹侧组基因编码EGF/转化生长因子阿尔法型生长因子(Spitz)和果蝇EGF受体(EGF-r)。Rho是腹侧群基因中唯一已知的成员，其表达模式与需要腹侧群基因活性的细胞相对应。Rho编码一种膜蛋白(Rho)，并可能通过结合Spitz生长因子而放大EGF-R信号发挥作用。由于EGF-R信号通路在进化过程中高度保守，这些对果蝇的研究很可能与包括人类在内的其他物种直接相关。以下是该建议的具体研究目标：1)确定Rho蛋白的亚细胞定位。Rho蛋白是否像预测的那样位于细胞表面，作为受体复合体的一部分发挥作用？Rho是否位于细胞与细胞密切接触的部位？2)研究Rho蛋白的生化功能，并确定Rho是否与其他蛋白质发生物理作用。Rho蛋白是否与其他蛋白(如EGF-R信号通路的组成部分)发生物理相互作用？SPI是EGF-R的配体吗？Rho是否介导细胞的差异黏附？3)决定Rho是否专用于放大SPI-EGF-R信号，或者其他信号通路是否也被Rho激活？EGF-R途径各组成部分的转录下调依赖于Rho吗？*

9318242 Bier The goal of this proposal is to understand the function of the rhomboid (rho) gene that is required for several distinct developmental events including : early dorsal- ventral pattern formation in the Drosophila embryo, the formation of embryonic sensory organs, and the formation of adult wing veins. rho is one of several genes (referred to as ventro-lateral group genes) required for the formation of these diverse structures. Other ventro-lateral group genes encode an EGF/TGF alpha type of growth factor (spitz) and the Drosophila EGF-receptor (egf-r). rho is the only known member of the ventro-lateral group of genes expressed in a spatially localized pattern corresponding to the cells requiring the activity of ventro-lateral group genes. rho encodes a membrane protein (Rho) and may act by amplifying EGF-R signaling in response to binding the Spitz growth factor. Because the EGF-R signaling pathway has been highly conserved during evolution it is likely that these studies in Drosophila will be directly relevant to other species, including humans. The following are specific research goals for this proposal: 1) Determine the subcellular localization of the Rho protein. Is the Rho protein located on the cell surface as predicted for a protein functioning as part of a receptor complex? Is Rho located at sites of intimate cell- cell contact? 2) Investigate how the Rho protein functions biochemically and determine whether Rho physically interacts with other proteins. Does the Rho protein physically interact with other proteins (e.g. components of the EGF-R signaling pathway)? Is Spi a ligand for EGF-R? Does Rho mediate differential cell adhesion? 3) Determine whether rho is dedicated to amplifying Spi-EGF-R signaling or are other signaling pathways also activated by Rho? Does transcriptional down regulation of components of the EGF-R pathway depend on rho? ***