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

描述(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方面起着重要作用。尽管在体外剪接简单的前-mRNA所需的分子事件已经相当清楚，但我们在很大程度上仍然不知道复杂的剪接过程在体内是如何调控的。理解这个过程是如何工作的是至关重要的，因为RNA剪接中的错误与包括癌症在内的各种人类疾病有关。这个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。具体地说，我们研究了果蝇发育开关基因SXL的剪接调控。在我们早期研究的基础上，我们提出了一种新的机制，即SXL基因的雌性特异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自己的剪接模式。正如提案中所概述的，我们正在继续利用果蝇遗传学来鉴定和描述参与剪接调控这一生物学上重要的例子的蛋白质的功能。我们还在使用生化方法来测试已知与我们在体内观察到的模型相兼容的模型。最后，我们正在首次调查用于控制SXL的机制是否具有组织特异性和性别特异性。这些研究的综合数据将提供与剪接调控相关的复杂性的洞察力，而这些剪接调控仅仅通过在组织培养细胞中进行的研究是无法获得的。由于从人类到苍蝇的剪接机制的显著保守，我们使用非常容易驯服的果蝇系统开发的范例与人类生物学相关。

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.