DISCS-LOST IN APICAL CELL JUNCTIONS IN DROSOPHILA EYE

描述（逐字摘自申请人摘要）：果蝇复眼 由成象盘上皮发育而来。光盘的区分 原基进入成人眼睛涉及动态的细胞与细胞相互作用 连续的细胞命运决定。我们的长期目标是了解 视网膜分化过程中顶端细胞与细胞接触的分子基础。 Discs-lost (Dlt) 是一种新型 PDZ 结构域蛋白，位于顶端 膜。 Dlt 对于建立胚胎的顶端-基底极性至关重要 上皮细胞。 Dlt 也是成虫增殖和/或存活所必需的。 盘细胞。在发展中的眼睛中，Dlt 似乎对于规范至关重要 色素细胞的命运和支持感光器的视网膜底的形成 视网膜上皮内的簇。 Dlt 蛋白包含四个参与蛋白质-蛋白质相互作用的 PDZ 结构域。 这表明 Dlt 可能在眼睛发育过程中发挥多种作用 与特定的蛋白质伙伴相互作用。研究PDZ域的作用 Dlt 和相互作用的蛋白质，提出了四个具体目标。首先， 含有一系列截短的 Dlt 构建体的转基因果蝇将被 生成的。将在体内测试突变构建体以确定是否 椎间盘生长和/或顶膜需要特定的 PDZ 结构域 Dlt 的本地化其次，由于 Dlt 的丢失似乎会导致 原代色素细胞，将进行克隆分析以确定哪些 细胞类型需要表达 Dlt 以正确指定原色 细胞。第三，Dlt 和 Delta 之间的相互作用将在 生化、遗传和免疫细胞化学水平以确认我们的初步结果 有证据表明 Dlt 与 Delta 存在遗传相互作用，Delta 是一种膜结合配体 缺口。第四，Dlt 与 Crumbs (Crbintra) 的细胞内结构域相互作用。 Crbintra 的过度表达和 Dlt 的缺失会导致类似的缺陷 眼，表明 Crbintra 作为 Dlt 的显性负向因子。的 Crbintra 引起的眼睛表型将被用作有效的遗传系统 发现影响眼睛 Dlt 和 Crb 功能的新突变。 已发现与 Dlt 类似的脊椎动物蛋白质序列。这些研究关于 Dlt 和 Notch 信号蛋白将提供对其功能的有用见解 细胞间相互作用和信号传导中脊椎动物同源物的研究。

DESCRIPTION (Verbatim from applicant's abstract): The Drosophila compound eye develops from the imaginal disc epithelium. Differentiation of a disc primordium into an adult eye involves dynamic cell-cell interactions and successive cell fate decisions. Our long-term objective is to understand the molecular basis of apical cell-cell contacts during retinal differentiation. Discs-lost (Dlt), a novel PDZ domain protein, is localized at the apical membranes. Dlt is essential for establishing apico-basal polarity of embryonic epithelia. Dlt is also required for proliferation and/or survival of imaginal disc cells. In the developing eye, Dlt appears to be crucial for specification of pigment cell fates and formation of retinal floor to support photoreceptor clusters within the retinal epithelium. Dlt protein contains four PDZ domains involved in protein-protein interactions. This suggests that Dlt may play multiple roles during eye development by interacting with specific protein partners. To study the role or PDZ domains of Dlt and interacting proteins, four specific aims are proposed. First, transgenic flies containing a series of truncated Dlt constructs will be generated. Mutant constructs will be tested in vivo to determine whether specific PDZ domains are required for disc growth and/or apical membrane localization of Dlt. Second, since loss of Dlt appears to cause misrouting of primary pigment cells, clonal analysis will be performed to determine which cell types need to express Dlt for correct specification of primary pigment cells. Third, interaction between Dlt and Delta will be examined at biochemical, genetic and immunocytochemical levels to confirm our preliminary evidence that Dlt interacts genetically with Delta, a membrane-bound ligand for Notch. Fourth, Dlt interacts with intracellular domain of Crumbs (Crbintra). Overexpression of Crbintra and loss of Dlt results in similar defects in the eye, suggesting that Crbintra acts as a dominant-negative factor for Dlt. The eye phenotype caused by Crbintra will be used as an efficient genetic system to find new mutations affecting Dlt and Crb function in the eye. Vertebrate protein sequences similar to Dlt have been found. These studies on Dlt and Notch signaling proteins will provide useful insights into the function of vertebrate homologs in cell-cell interaction and signaling.