Regulation of Gene Expression by Dietary Fat

膳食脂肪对基因表达的调节

• 批准号: 6741479
• 负责人: LISA M SALATI
• 金额: $ 22.06万
• 依托单位: WEST VIRGINIA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-08-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6741479
• 关键词: dietary lipid; gene expression; genetic regulation; genetic transcription; genetically modified animals; glucose 6 phosphate dehydrogenase; immunoprecipitation; laboratory mouse; laboratory rat; liver cells; mass spectrometry; messenger RNA; nutrition related tag; phosphorylation; polymerase chain reaction; posttranscriptional RNA processing; precursor mRNA; protein binding; protein structure function; tissue /cell culture; transfection; unsaturated fats; unsaturated fatty acids; western blottings

DESCRIPTION (provided by applicant): For at least three decades, the American public has been encouraged to decrease their consumption of total dietary fat and to increase the ratio of polyunsaturated to saturated fatty acids in the diet. Yet the molecular details by which fatty acids act within cells is not well understood. The long-range goal is to understand how the addition of polyunsaturated fat in the diet regulates intracellular metabolism in the liver. The objective of this application is to define the steps by which polyunsaturated fatty acids inhibit posttranscriptional steps during gene expression using G6PD as our model gene. The central hypothesis of the application is that efficient splicing of the G6PD transcript requires the binding of a specific splicing co-activator protein to a splicing enhancer sequence in an exon of the pre-mRNA. The addition of polyunsaturated fat to the diet inhibits the activity of the splicing co-activator, decreasing pre-mRNA splicing and thereby targeting the transcript for degradation. The rationale is that this mechanism is not unique to G6PD but is shared by other genes involved in intermediary metabolism including those that are also regulated at transcriptional steps. This additional level of regulation would provide the cell with both redundant mechanisms to ensure regulated expression of these proteins and a more rapid response to changing environmental conditions. G6PD provides an ideal model to study this novel form of posttranscriptional regulation because the absence of transcriptional changes makes interpretation of the data much easier. Experiments to characterize the sequence of the exon splicing enhancer element are described in Specific Aims 1. Specific Aim 2 tests if a splicing co-activator protein binds the RNA element and if mutations in the element block binding of this protein. A long-term goal of this project has been to identify the mechanism by which dietary fat regulated gene expression. In Specific Aim 3, transgenic mice expressing G6PD RNA reporters will be used to test if the exon splicing enhancer is involved in dietary regulation of gene expression. Identification of the molecular pathway by which dietary fat alters intracellular metabolism is critical to understanding the molecular basis for diseases such as obesity, diabetes and atherosclerosis that are associated with over-consumption of fat, and can lead to improved strategies for treatment of these diseases via diet or drug intervention.

描述（由申请人提供）：至少三十年来，一直鼓励美国公众减少其总饮食脂肪的消费，并增加饮食中多不饱和与饱和脂肪酸的比率。然而，尚不清楚脂肪酸在细胞内作用的分子细节。远程目标是了解饮食中多不饱和脂肪的添加如何调节肝脏中细胞内代谢。该应用的目的是定义多不饱和脂肪酸使用G6PD作为模型基因的基因表达期间的转录后步骤的步骤。应用的中心假设是，G6PD转录本的有效剪接需要特定的剪接共激活因子蛋白与前MRNA外显子中剪接增强子序列的结合。在饮食中添加多不饱和脂肪会抑制剪接共激活因子的活性，减少前MRNA剪接，从而靶向转录本以降解。理由是，这种机制不是G6PD独有的，而是由中介代谢中涉及的其他基因共享的，包括在转录步骤中也受到调节​​的基因。这种额外的调节水平将为细胞提供两种冗余机制，以确保这些蛋白质的调节表达以及对不断变化的环境条件的更快反应。 G6PD提供了一个理想的模型来研究这种新型的转录后调节形式，因为缺乏转录变化使对数据的解释变得更加容易。特定目的1中描述了表征外显子剪接增强子元件序列的实验。特定的目标2测试如果剪接共激活蛋白结合了RNA元素，并且该蛋白元素块中的突变是否在该蛋白质的元素块结合中。该项目的一个长期目标是确定饮食脂肪调节基因表达的机制。在特定的目标3中，表达G6PD RNA报告基因的转基因小鼠将用于测试外显子剪接增强子是否参与基因表达的饮食调节。鉴定饮食脂肪会改变细胞内代谢的分子途径对于了解肥胖，糖尿病和动脉粥样硬化等疾病的分子基础至关重要，这些疾病与脂肪过度消耗有关，并且可以通过饮食或药物干预来改善这些疾病治疗这些疾病的策略。