Transcriptome processing networks in skeletal muscle: mechanisms and functions

描述（由申请人提供）：除了基因输出的转录调控外，哺乳动物基因组在前mRNA加工过程中通过选择性剪接和选择性3' mRNA末端产生广泛的转录组和蛋白质组多样性。至于转录，转录组加工响应于动态生理需要而被广泛调节。转录组加工的调节涉及由RNA结合蛋白控制的互连网络，所述RNA结合蛋白结合到受调节加工位点附近的前mRNA内的优选序列基序。该项目的长期目标是确定成人骨骼肌中转录组加工的程度、调节机制和功能后果。转录组加工网络的破坏导致骨骼肌疾病，但对正常调节的程度或功能知之甚少。在这个建议的第一部分，我们将确定由福克斯家族的RNA结合蛋白在骨骼肌中控制的调控网络，并确定它们在成肌细胞分化过程中的功能。我们将使用骨骼肌中表达的两个Fox基因的组织特异性和诱导性敲除来确定成人骨骼肌中肌纤维和卫星细胞的调控网络的功能。在第二部分的建议，我们将确定额外的监管网络在成肌细胞分化过程中使用双色剪接报告在高通量RNAi筛选。所获得的知识将被导向理解这些网络在成人骨骼肌中的作用。这一结果将提供一个新的理解核转录后调节的作用，在不同的稳态功能的成人骨骼肌及其修复能力。这种理解对于开发和应用新的治疗策略来治疗对骨骼肌功能产生负面影响的疾病是重要的。 公共卫生相关性：基因表达的转录后调控，如选择性剪接和3'末端加工，在控制基因表达中起着重要作用。本研究拟对骨骼肌分化过程中和成年骨骼肌组织中的选择性剪接和3'端加工机制进行研究。这些信息将用于了解骨骼肌的正常过程，有助于未来开发逆转或规避疾病的治疗方法。

DESCRIPTION (provided by applicant): In addition to transcriptional regulation of gene output, mammalian genomes produce extensive transcriptome and proteome diversity by alternative splicing and selection of alternative 3' mRNA ends during pre-mRNA processing. As for transcription, transcriptome processing is extensively regulated in response to dynamic physiological needs. The regulation of transcriptome processing involves interconnected networks controlled by RNA binding proteins that bind to preferred sequence motifs within the pre-mRNA near the sites of regulated processing. The long term goal of this project is to determine the extent, regulatory mechanisms, and functional consequences of transcriptome processing in adult skeletal muscle. The disruption of transcriptome processing networks contributes to disease in skeletal muscle yet little is known regarding the extent or functions of normal regulation. In the first part of this proposal, we will identify the regulatory networks controlled by the Fox family of RNA binding proteins in skeletal muscle and determine their functions during myoblast differentiation. We will use tissue specific and inducible knock outs of the two Fox genes expressed in skeletal muscle to determine the functions of the regulatory networks in myofibers and satellite cells in adult skeletal muscle. In the second part of the proposal, we will identify additional regulatory networks operative during myoblast differentiation using a bichromatic splicing reporter in high throughput RNAi screens. Knowledge gained will be directed toward understanding the roles of these networks in adult skeletal muscle. The results will provide a new understanding of the role of nuclear post-transcriptional regulation in the diverse homeostatic functions of adult skeletal muscle and its capacity for repair. This understanding is important for development and application of novel therapeutic strategies to conditions that negatively affect skeletal muscle function. PUBLIC HEALTH RELEVANCE: Post-transcriptional regulation of gene expression, such as alternative splicing and 3' end processing, play a large role in controlling gene expression. This proposal studies the mechanisms of alternative splicing and 3' end processing during skeletal muscle differentiation and in adult skeletal muscle tissue. This information will be used to understand normal processes in skeletal muscle useful for future development of therapeutic approaches to reverse or circumvent disease.