Pros/Prox1 and Lens Development

描述（由申请人提供）：在脊椎动物中，一个功能性晶状体需要晶状体纤维细胞分化、伸长和表达大量适当晶体蛋白分子的能力。任何影响这些过程的因素都是有害的，并可能导致白内障的形成。敲除研究表明，小鼠转录因子Proxl调节晶状体纤维伸长和晶体蛋白基因表达。不幸的是，Proxl基因敲除的动物在胚胎期第13.5天死亡，这使得进一步分析这种表型变得困难。我们的初步数据表明，procl的果蝇同源物，称为普洛斯彼罗（Pros），也是晶状体形成所必需的。与Proxl类似，Pros影响晶状体细胞分化和晶体蛋白基因表达。这是首次报道无脊椎动物和脊椎动物的晶状体发育具有相似的转录调控途径。有趣的是，Pros和Proxl在晶状体细胞分化过程中也表现出核表达和细胞质表达，这表明这些蛋白也具有非转录作用。本研究旨在探讨pro / prox1介导的晶状体发育的进化保守基础。为此，我们将：1)更精确地表征Pros在晶状体细胞发育中的作用；2)测试Pros在晶状体发育中的细胞内定位的贡献；3)表征Pros/Prox1转录因子家族的功能保护。这些研究将结合体外生化和转录调控分析、定点诱变和体内遗传分析，为Pros/Prox1蛋白在晶状体发育过程中的功能提供一个广阔的视角。这项工作将为开展更深入的遗传研究提供必要的框架，旨在确定正常晶状体发育所需的关键调控途径，作为了解先天性和年龄相关性白内障患者中这些途径的哪些方面受到干扰的手段。白内障是由于我们的晶状体不能正常发育或维持而造成的。不幸的是，我们对正常晶状体是如何形成的了解不多，这使得我们很难设计出预防晶状体异常形成的方法，比如白内障。这一建议的重点是开发一种新的遗传模型，使我们能够快速识别晶状体发育所必需的新途径，作为规避导致白内障形成和失明的事件的手段。

DESCRIPTION (provided by applicant): In vertebrates, a functional lens requires the ability of lens fiber cells to differentiate, elongate, and express abundant levels of the appropriate crystallin molecules. Factors which affect any of these processes are detrimental and can lead to the formation of cataract disease. Knockout studies have shown that the mouse transcription factor Proxl regulates lens fiber elongation and crystallin gene expression. Unfortunately, Proxl knockout animals die by embryonic day 13.5, making further analysis of this phenotype difficult. Our preliminary data demonstrate that the Drosophila ortholog of Proxl, called Prospero (Pros), is also necessary for lens formation. Similar to Proxl, Pros affects lens cell differentiation and crystallin gene expression. This is one of the first reports that lens development in invertebrates and vertebrates shares similar transcriptional regulatory pathways. Interestingly, Pros and Proxl also exhibit both nuclear and cytoplasmic expression during lens cell differentiation, suggesting a non-transcriptional role for these proteins as well. The studies outlined here are aimed to explore the evolutionary conserved basis for Pros/Prox1-mediated lens development. For this, we will: 1) more precisely characterize the role for Pros in lens cell development, 2) test the contribution of Pros intracellular localization in lens development, and 3) characterize functional conservation with the Pros/Prox1 family of transcription factors. These studies will use a combination of in vitro biochemical and transcriptional regulatory assays, site-directed mutagenesis, and in vivo genetic analyses to provide a broad perspective on how Pros/Prox1 proteins function during lens development. This work will provide the framework necessary to perform more in-depth genetic studies aimed at identifying key regulatory pathways necessary for normal lens development as a means for understanding what aspects of these pathways are disturbed in patients suffering from congenital and age- related cataracts. LAY: Cataracts result from the failure of our lens to properly develop or to be maintained. Unfortunately, not much is known about how a normal lens develops, making it difficult for us to devise ways to prevent abnormal lens formation such as in cataract disease. This proposal is focused on developing a new genetic model that will allow us to rapidly identify new pathways that are necessary for lens development as a means to circumvent events that lead to cataract formation and blindness.