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mRNA前加工过程中通过选择性剪接和选择性3' mRNA末端的选择产生广泛的转录组和蛋白质组多样性。至于转录，转录组加工受到广泛调控，以响应动态生理需求。转录组加工的调控涉及由RNA结合蛋白控制的相互连接的网络，这些结合蛋白结合到靠近调节加工位点的前mrna内的首选序列基序。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。转录组处理网络的破坏有助于骨骼肌疾病，但对正常调节的程度或功能知之甚少。在本提案的第一部分，我们将确定骨骼肌中Fox家族RNA结合蛋白控制的调控网络，并确定其在成肌细胞分化过程中的功能。我们将使用组织特异性和诱导敲除骨骼肌中表达的两个Fox基因来确定成人骨骼肌肌纤维和卫星细胞中的调节网络的功能。在提案的第二部分，我们将在高通量RNAi筛选中使用双色剪接报告基因来识别在成肌细胞分化过程中起作用的其他调控网络。所获得的知识将用于理解这些网络在成人骨骼肌中的作用。这些结果将为细胞核转录后调控在成人骨骼肌多种稳态功能及其修复能力中的作用提供新的认识。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很重要的。

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.