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.

项目摘要 MAF1是基因转录的保守营养和应激敏感的阻遏物。最著名的作为酵母中RNA聚合酶III转录的主要调节剂，MAF1也已被证明会影响 RNA聚合酶II在哺乳动物细胞中转录的选择基因的表达。 MAF1镇压 RNA聚合酶III调节转移RNA，5S rRNA和其他丰富的非编码RNA的合成在每个细胞中，这共同占总RNA的约15％。因此，MAF1功能被认为对代谢经济。最近的戏剧性证明了这一观点的发现，发现老鼠有整体 MAF1的身体敲除苗条，对饮食诱导的肥胖症和非酒精性脂肪肝具有深远的抗性疾病。 MAF1 KO小鼠的代谢效率低下，能量消耗增加，并且具有延长寿命指示健康的改善。当前的理解是增加了RNA Pol III转录每个组织都对核苷酸的能量昂贵合成的需求施加了这种需求，以改变能源利用和存储之间的平衡。因此，该项目的长期目标是确定没有MAF1改变基因表达和代谢以改变代谢效率和能量支出。该提案的目的I将研究如何在关键代谢中改变基因表达通过转录组和核糖体分析以及通过研究tRNA种群对MAF1 - / - 小鼠的组织翻译效率和保真度。 AIM II将确定能量增加的代谢变化通过靶向代谢物分析，MAF1 - / - 小鼠的支出。这些研究将集中于中央代谢途径，将通过稳定的全身脂解和通量的同位素测量来补充我们假设的戊糖磷酸途径，与增强的供应和小鼠代谢能量的消耗。 AIM III将研究RNA POL III转录的作用通过高度丰富的非编码的不受约束的合成，MAF1 - / - 小鼠中的能量消耗 RNA，包括转移RNA和非特异性转录。新生的伸长笔录测序将定位并量化RNA POL III分子全基因组和新的小鼠模型以抑制 MAF1 KO表型直接或间接地是由RNA Pol III转录升高的。最后，研究在AIM IV中，IV将通过诱导且全身性的Cre-确定年轻小鼠和成年小鼠中MAF1的损失是否是否介导的重组增加了代谢效率低下。这些实验有望支持 MAF1的产后功能对代谢经济至关重要的概念，同时提供强大的 MAF1作为抗肥胖药物靶标的潜力的证明。