Metabolism and Epigenetics

项目摘要 该项目旨在揭示在编码基因中发现的致癌突变是如何 中枢代谢酶在多种类型的癌症中引起表观遗传后果 他们就是在那里被发现的。实地研究表明，影响其中一种酶的突变， 异柠檬酸脱氢酶，产生一种称为2-羟基戊二酸(2-HG)的肿瘤代谢物 它可以抑制去除DNA和组蛋白的甲基化修饰的酶。哪一个 甲基化靶标在癌症中发挥关键作用尚不清楚。PI已经表明了完全相同的 人类癌症中发现的突变，当被工程改造到酿酒酵母中时 生产2-HG。他还发现了一种酵母菌基因，这种基因编码一种代谢2-羟色胺的酶。 HG。使用一种巧妙的方法来干扰异染色质，导致了 通过这些突变，异染色质似乎超稳定，而不是通过抑制DNA 去甲基化，但通过抑制特定的赖氨酸36甲基化物种的去甲基化 组蛋白H3。拟议的实验通过直接生化扩展了这些遗传推断。 测试。他们将测试2-HG是否影响染色质的其他结构- 建立了他们擅长的基因组学方法。进一步的目标延伸了他们令人惊讶的 发现2-HG也是由野生型细胞制造的。通过利用系统的力量 基因阵列(SGA)技术，他们将通过识别2-HG在细胞中的自然作用 当突变时，使细胞对升高的2-HG敏感的所有基因。酵母菌模型 琥珀酸脱氢酶和富马酸酶的致癌等位基因将被制作并测试 表观遗传影响，如果发现，影响的机制将被建立。建立在 通过异柠檬酸脱氢酶突变体的酵母模型的成功，PI完成了 到目前为止成功的中试筛选出了5个影响异染色质稳定性的基因 对新陈代谢的影响，并建议完成筛查，估计恢复或50- 100个基因，代表了一组近乎全面的代谢和 表观遗传学。每种扰动的表观遗传效应背后的机制将被确定。

Project Summary This project is designed to reveal how the cancer-driver mutations found in the genes encoding central metabolic enzymes cause epigenetic consequences in the multiple types of cancers in which they are found. Work in the field indicates that mutations affecting one of these enzymes, isocitrate dehydrogenase, produce an onco-metabolite known a 2-hydroxyglutarate (2-HG) which can inhibit enzymes that remove methyl modifications of DNA and histones. Which methylated targets play critical roles in cancers is unclear. The PI has show that the very same mutations found in human cancer, when engineered into the yeast Saccharomyces cerevisiae produce 2-HG. He has also found a yeast gene that encodes an enzyme that metabolizes 2- HG. Using an ingenious assay for pertubations of heterochromatin, the overproduction caused by these mutations appears to hyper-stabilize heterochromatin, not by inhibiting DNA demethylation, but by inhibiting demethylation of a specific methylated species of lysine 36 on histone H3. The proposed experiments extend these genetic inferences by direct biochemical tests. They will test whether 2-HG is affecting any of the other structures of chromatin by well- established genomic methods that they are expert in. Further aims extend their surprising discovery that 2-HG is also made by wild-type cells. By harnessing the power of systematic genetic array (SGA) technology, they will identify the natural role of 2-HG in cells by identifying all genes that, when mutant, render cells sensitive to elevated 2-HG. Yeast models for the cancer-driving alleles of succinate dehydrogenase and fumarase will be made and tested for epigenetic impacts, and if found, the mechanism of the impact will be established. Building upon success with the yeast model of isocitrate dehydrogenase mutants, the PI has completed a successful pilot screen that identified 5 genes so far that affect heterochromatin stability through effects on metabolism, and propose completing the screen with an estimated recovery or 50- 100 genes, representing a near-comprehensive set of intersections betweeen metabolism and epigenetics. The mechanism behind each perturbations's epigenetic effect will be determined.