Regulation of Sex-lethal pre-mRNA splicing during Drosophila development

描述（由申请人提供）：组织特异性选择性剪接在后生动物的基因表达调控中起着重要作用。虽然在体外拼接一个简单的前mRNA所需的分子事件是相当好的理解，我们仍然在很大程度上无知的复杂过程中剪接是如何在体内调节。了解这个过程是如何工作的是至关重要的，因为RNA剪接的错误与各种人类疾病，包括癌症。该项目的长期目标是了解外显子跳跃的调控，外显子跳跃是人类最常见的选择性剪接形式之一。具体而言，我们研究了果蝇发育开关基因Sex-lethal（Sxl）的剪接调控。基于我们早期的研究，我们提出了一种新的机制，通过这种机制，Sxl基因的女性特异性产物通过与剪接体的核心成分相互作用并使其失活来控制其自身的剪接模式。正如提案中所概述的，我们正在继续利用果蝇遗传学来识别和描述参与剪接调节的生物学重要例子的蛋白质的功能。我们还使用生物化学方法来测试已知与我们在体内观察到的兼容的模型。最后，我们正在调查，第一次，是否用于控制Sxl的机制是组织，以及性别特异性。这些研究的综合数据将为了解与剪接调节相关的复杂性提供见解，而这些复杂性根本无法通过仅在组织培养细胞中进行的研究获得。由于从人类到果蝇的剪接机制的显著保守性，我们使用非常易处理的果蝇系统开发的范例与人类生物学有关。

DESCRIPTION (provided by applicant): Tissue specific alternative splicing plays a prominent role in regulating gene expression in metazoans. Although the molecular events required to splice a simple pre-mRNA in vitro are fairly well understood, we remain largely ignorant of how the complex process of splicing is regulated in vivo. An understanding of how this process works is of fundamental importance since errors in RNA splicing are associated with a variety of human diseases, including cancer. The long-term goal of this project is to understand regulation by exon skipping, one of the most common forms of alternative splicing in humans. Specifically, we study the splicing regulation of the Drosophila developmental switch gene Sex-lethal (Sxl). Based on our earlier studies, we propose a novel mechanism by which the female specific product of the Sxl gene controls its own splicing pattern by interacting with, and inactivating, core components of the spliceosome. As outlined in the proposal, we are continuing to exploit Drosophila genetics to identify and delineate the function of proteins that participate in this biologically important example of splicing regulation. We are also using biochemical approaches to test the models that are known to be compatible with what we observe in vivo. Lastly, we are investigating, for the first time, whether the mechanism utilized to control Sxl is tissue-, as well as sex-specific. The combined data from these studies will provide insights into the complexities associated with splicing regulation that simply cannot be obtained via studies carried out solely in tissue culture cells. Due to the remarkable conservation of the splicing machinery from humans to flies, the paradigms we develop using the very tractable Drosophila system are relevant to human biology.