DISCS-LOST IN APICAL CELL JUNCTIONS IN DROSOPHILA EYE

描述(逐字摘自申请者摘要)：果蝇复眼 由假想的盘状上皮发育而来。盘的辨别 成人眼的原基涉及动态的细胞-细胞相互作用和 连续的细胞命运决定。我们的长期目标是了解 视网膜分化中顶端细胞-细胞接触的分子基础。 Diss-Lost(DLT)是一种新的PDZ结构域蛋白，定位于根尖 膜。DLT是建立胚胎顶基极性所必需的 上皮细胞。DLT对于神经母细胞瘤的增殖和/或存活也是必需的 圆盘细胞。在发展中的眼中，DLT似乎是规范的关键 色素细胞命运和视网膜底部的形成以支持光感受器 聚集在视网膜上皮细胞内。 DLT蛋白含有四个参与蛋白质间相互作用的PDZ结构域。 这表明DLT可能通过以下方式在眼睛发育过程中发挥多重作用 与特定的蛋白质伙伴相互作用。研究PDZ域的作用或作用 DLT和相互作用蛋白，提出了四个具体目标。第一, 含有一系列截短DLT结构的转基因果蝇将被 已生成。突变结构将在体内进行测试，以确定 椎间盘生长和/或根尖膜需要特定的PDZ结构域 DLT的本地化。第二，由于DLT的丢失似乎会导致误路由 原代色素细胞，将进行克隆分析以确定 细胞类型需要表达DLT才能正确指定原色 细胞。第三，DLT和Delta之间的交互将在 生化、遗传和免疫细胞化学水平来确认我们的初步 DLT与Delta基因相互作用的证据，Delta是一种膜结合配体，用于 开槽。第四，DLT与Crumbs的胞内区(Crbintra)相互作用。 CrbintrA的过表达和DLT的丢失导致了类似的缺陷 眼，提示CRBINTRA是DLT的显性-负性因子。这个 由Crbintra引起的眼睛表型将作为一种有效的遗传系统用于 在眼睛中发现影响DLT和CRB功能的新突变。 类似于DLT的脊椎动物蛋白质序列已经被发现。这些研究是关于 DLT和Notch信号蛋白将为了解其功能提供有用的信息 脊椎动物的同源物在细胞间的相互作用和信号传递中的作用。

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.