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Mitochondrial 2-hydroxyglutarate dehydrogenases modulate the cellular epitranscriptome

线粒体 2-羟基戊二酸脱氢酶调节细胞表观转录组

基本信息

批准号：
10322194
负责人：
Ricardo C Aguiar
金额：
$ 31万
依托单位：
UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-01-01 至 2024-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10322194
关键词：
Acetyl Coenzyme A Acetylation Agreement B-Lymphocytes Biological Models Biological Process Cell Line Cells Chemicals Cysteine DNA DNA Methylation Data Dioxygenases Distal Enzymes Epigenetic Process Exercise Gene Expression Gene Expression Profile Generations Genes Genetic Models Genetic Transcription Hexosamines Histones Homeostasis Human Hypermethylation In Vitro Knowledge Link Location Mediating Messenger RNA Metabolism Methylation Methyltransferase Mitochondria Mitochondrial RNA Mixed Function Oxygenases Modeling Modification Mutation Nuclear O-GlcNAc transferase Organelles Output Oxidoreductase Pathology Pathway interactions Physiology Play Post-Translational Protein Processing Production Proteins RNA RNA methylation Reactive Oxygen Species Reporter Research Role S-Adenosylmethionine Signal Transduction Stem Cell Development Testing Therapeutic Transcriptional Activation Transgenic Mice Work alpha ketoglutarate chromatin immunoprecipitation demethylation epitranscriptome field study histone demethylase histone methylation human disease in vitro Model in vivo loss of function mitochondrial metabolism mouse model novel oxidation

项目摘要

There is increasing recognition of mitochondria as signaling organelles. An important facet of this “adjunct” mitochondrial function is epigenetic modulation, as exemplified by the generation of acetyl-CoA and S- adenosylmethionine used in the acetylation and methylation, respectively, of DNA and histones. In addition, alpha-ketoglutarate (αKG) and 2-hydroxyglutarate (2-HG), metabolites generated almost exclusively in the mitochondria, are found to modulate the activity of αKG-dependent dioxygenases, including TET DNA hydroxylases and histone demethylase (HDM), thus controlling DNA and histone methylation. Notably, our group discovered that αKG activates and 2-HG inhibits FTO and ALKBH5, RNA demethylases that act on N6- methyladenosine (m6A), a reversible chemical modification of mRNA (the epitranscriptome) that influences gene expression. Similar to other epigenetic marks, RNA methylation is dynamically controlled and m6A abundance influence various biological functions, while its misregulation associates with human diseases. Considering that αKG/2-HG are generated mainly by intermediary mitochondrial metabolism, and that the activity of RNA demethylases are modulated by these metabolites, it is reasonable to speculate that mitochondria play an important role in the control of RNA methylation homeostasis. In particular, we postulate that the mitochondrial enzymes D-2- and L-2-hydroxyglutarate dehydrogenase (D2HGDH and L2HGDH), which catalyze the interconversion of 2-HG to αKG, are integral to the interplay between mitochondrial metabolism and the control of RNA methylation. This hypothesis is supported by our earlier discovery that loss of function D2HGDH mutations leads to decreased activity of the αKG-dependent TET and HDM enzymes. We recently expanded on this concept by identifying upstream signals that regulate D2HGDH and L2HGDH expression/activity. Using ChIP assays, inducible cell lines and a transgenic mouse model we discovered that MYC transcriptionally activates D2HGDH and L2HGDH, and that in a D2/L2HGDH/αKG-dependent manner it induces FTO and ALKBH5 function leading to RNA demethylation in vitro and in vivo. Remarkably, we found that the MYC-D2/L2HGDH-αKG axis also promotes the nuclear accumulation of FTO and ALKBH5, in association with enhanced O-GlcNAcylation, a post-translational modification executed by another mitochondrial enzyme, O-GlcNAc transferase (OGT). Here, using multiple genetic models in vitro and in vivo, we will test the hypothesis that a novel mitochondrial signaling axis, which includes MYC at the proximal point, D2/L2HGDH and OGT at the center, and, distally, FTO/ALKBH5 activity, controls the cellular epitranscriptome. Our specific aims are: 1) characterize the contribution of D2HGDH/L2HGDH and of intermediate metabolites to the control of m6A levels, 2) determine the mechanistic basis for the increased O-GlcNAcylation mediated by the MYC-D2/L2HGDH-αKG axis and its role in promoting RNA demethylation, 3) define a mitochondrial metabolism-dependent methylRNA/gene expression signature in human cells.

越来越多的人认识到线粒体是信号细胞器。这个“辅词”的一个重要方面是