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调节后生动物的基因表达中起着突出作用。尽管在体外剪接一个简单的pre-mRNA所需的分子事件已经被很好地理解了，但我们对剪接的复杂过程在体内是如何调节的仍然知之甚少。了解这一过程是如何工作的至关重要，因为RNA剪接错误与包括癌症在内的多种人类疾病有关。该项目的长期目标是了解外显子跳变的调控，这是人类中最常见的选择性剪接形式之一。具体来说，我们研究了果蝇发育开关基因性致死性（Sxl）的剪接调控。基于我们之前的研究，我们提出了一种新的机制，即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和失活来控制自己的剪接模式。正如提案中概述的那样，我们将继续利用果蝇遗传学来识别和描述参与这种生物学上重要的剪接调节的蛋白质的功能。我们还使用生化方法来测试已知与我们在体内观察到的相容的模型。最后，我们首次研究了用于控制Sxl的机制是否具有组织特异性和性别特异性。来自这些研究的综合数据将提供对剪接调节的复杂性的见解，这些复杂性是无法通过单独在组织培养细胞中进行的研究获得的。由于从人类到果蝇的剪接机制具有显著的保守性，我们利用非常容易处理的果蝇系统开发的范式与人类生物学相关。

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.