MAF1 Function and Metabolic Inefficiency

MAF1 功能和代谢低效

基本信息

批准号：
9688658
负责人：
IAN M WILLIS
金额：
$ 4.61万
依托单位：
ALBERT EINSTEIN COLLEGE OF MEDICINE, INC
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-09-21 至 2018-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9688658
关键词：
Address Affect Amino Acids Animals Anti-Obesity Agents Automobile Driving Biochemical Cell Respiration Cells Cellular Stress Citric Acid Cycle Clinical Code Complement Conceptions Consumption DNA Polymerase III Data Diet Drug Targeting Energy Metabolism Engineering Equilibrium Eukaryota Exhibits Futile Cycling Gene Deletion Gene Expression Genes Genetic Recombination Genetic Transcription Glycolysis Goals Grant Health Hepatic Human In Vitro Knock-in Mouse Knock-out Knockout Mice Knowledge Life Link Lipids Lipolysis Liver Longevity LoxP-flanked allele Mammalian Cell Measurement Measures Mediating Metabolic Metabolic Pathway Metabolism Methods Modeling Molecular Molecular Analysis Mus Mutation Nucleotides Nutrient Nutritional Obesity Obesity associated disease Open Reading Frames Pathway interactions Pentosephosphate Pathway Phenotype Polyamines Population Process Prokaryotic Cells Proteins RNA RNA Polymerase II RNA Polymerase III Recombinants Regulator Genes Reporting Repression Research Resistance Ribose Ribosomal RNA Role Single-Gene Defect Stress Testing Thinness Tissues Tracer Transcript Transcription Repressor/Corepressor Transfer RNA Translations Untranslated RNA Yeasts cost experimental study genome-wide hydrophilicity improved inorganic phosphate insight metabolic phenotype mouse model non-alcoholic fatty liver disease novel nucleotide metabolism obesity treatment postnatal reduced food intake resistance gene ribosome profiling stable isotope therapeutic target transcriptome young adult

项目摘要

Project Summary MAF1 is a conserved nutrient- and stress-sensitive repressor of gene transcription. Best known for its role as a master regulator of RNA polymerase III transcription in yeast, MAF1 has also been shown to affect the expression of select genes transcribed by RNA polymerase II in mammalian cells. MAF1 repression of RNA polymerase III regulates the synthesis of transfer RNAs, 5S rRNA and other abundant non-coding RNAs that together account for ~15% of total RNA in every cell. Thus, MAF1 function is thought to be important for metabolic economy. Recent dramatic proof of this view was provided by the finding that mice with a whole body knockout of Maf1 are lean and profoundly resistant to diet-induced obesity and non-alcoholic fatty liver disease. Maf1 KO mice are metabolically inefficient, have increased energy expenditure and have an extended lifespan indicative of improved health. The current understanding is that increased RNA pol III transcription in every tissue places such a demand on the energetically expensive synthesis of nucleotides that it alters the balance between energy utilization and storage. Thus, the long term goal of this project is to determine how the absence of MAF1 changes gene expression and metabolism to alter metabolic efficiency and energy expenditure. Aim I of this proposal will examine how gene expression has been altered in key metabolic tissues of Maf1-/- mice by transcriptome and ribosome profiling and by investigating tRNA population effects on translation efficiency and fidelity. Aim II will determine the metabolic changes underlying the increased energy expenditure of Maf1-/- mice by targeted metabolite profiling. These studies will focus on central metabolic pathways and will be complemented by stable isotope measurements of whole body lipolysis and flux through the pentose phosphate pathway, processes that we hypothesize are associated with the enhanced supply and consumption of metabolic energy in the mice. Aim III will investigate the role of RNA pol III transcription in driving energy expenditure in Maf1-/- mice through unrestrained synthesis of highly abundant non-coding RNAs, including transfer RNA and non-specific transcription. Nascent elongating transcript sequencing will locate and quantify RNA pol III molecules genome-wide and a new mouse model will be created to suppress Maf1 KO phenotypes that result directly or indirectly from elevated RNA pol III transcription. Finally, the studies in aim IV will determine whether loss of MAF1 in young and adult mice via inducible and systemic Cre- mediated recombination increases metabolic inefficiency. These experiments are expected to support the concept that the postnatal function of MAF1 is critical for metabolic economy while providing a powerful demonstration of the potential of MAF1 as an anti-obesity drug target.

项目概要 MAF1 是一种保守的营养和应激敏感的基因转录抑制因子。最出名的是它作为酵母中 RNA 聚合酶 III 转录的主调节因子，MAF1 也被证明可以影响哺乳动物细胞中 RNA 聚合酶 II 转录的选定基因的表达。 MAF1 抑制 RNA聚合酶III调节转移RNA、5S rRNA和其他丰富的非编码RNA的合成它们合计约占每个细胞总 RNA 的 15%。因此，MAF1 功能被认为对于代谢经济。最近的一项发现提供了这一观点的戏剧性证据，即小鼠具有完整的敲除 Maf1 的身体变得苗条，并且对饮食引起的肥胖和非酒精性脂肪肝有很强的抵抗力疾病。 Maf1 KO 小鼠代谢效率低下，能量消耗增加，寿命延长寿命表明健康状况有所改善。目前的理解是，RNA pol III 转录增加每个组织都对能量昂贵的核苷酸合成提出了如此大的要求，以至于它改变了能源利用与储存之间的平衡。因此，该项目的长期目标是确定如何 MAF1 的缺失会改变基因表达和代谢，从而改变代谢效率和能量支出。该提案的目标一将检查关键代谢中基因表达如何改变通过转录组和核糖体分析以及研究 tRNA 群体对 Maf1-/- 小鼠组织的影响翻译效率和保真度。目标 II 将确定能量增加背后的代谢变化通过目标代谢物分析对 Maf1-/- 小鼠的消耗进行分析。这些研究将集中于中枢代谢途径，并将通过全身脂肪分解和通量的稳定同位素测量来补充戊糖磷酸途径，我们假设与增加供应和相关的过程小鼠代谢能量的消耗。 Aim III 将研究 RNA pol III 转录在通过不受限制地合成高度丰富的非编码来驱动 Maf1-/- 小鼠的能量消耗 RNA，包括转移RNA和非特异性转录。新生的延伸转录本测序将在全基因组范围内定位和量化 RNA pol III 分子，并将创建一个新的小鼠模型来抑制 Maf1 KO 表型直接或间接由 RNA pol III 转录升高引起。最后，研究目标IV将确定年轻和成年小鼠中MAF1的丢失是否通过诱导性和系统性Cre- 介导的重组会增加代谢效率低下。这些实验预计将支持 MAF1 的产后功能对于代谢经济至关重要，同时提供强大的证明了 MAF1 作为抗肥胖药物靶点的潜力。