Molecular mechanisms and roles of the mammalian 2-oxoglutarate-dependent oxygenases AlkBH1 and AlkBH7

哺乳动物 2-氧化戊二酸依赖性加氧酶 AlkBH1 和 AlkBH7 的分子机制和作用

• 批准号: 442081128
• 负责人: Dr. Sabine Schneider
• 金额: --
• 依托单位: Department Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/442081128?language=en
• 关键词: Molecular; mechanisms; roles; mammalian; oxoglutarate

Independent from the DNA genetic code, gene and protein activity is controlled by epigenetic mechanisms through writing, reading and erasing specific epigenetic marks. These marks include the covalent modifications of histones, DNA and RNA with methyl groups. These methyl groups play an essential role in many cellular processes. Responsible for the spacial and temporal maintenance of these epigenetic marks is carried out by so called "writer" and "eraser" enzymes. Here enzymes belonging to the Fe2+- and 2-oxoglutarate (2OG; = α-ketoglutarate) dependent oxygenase family are particular prominent actors. About 70 members of the Fe(II)/2OG-family across all kingdoms of life are known to date. These enzymes use the cosubstrate 2OG to bind to ferrous iron and to activate molecular oxygen in order to catalyse the transfer of the molecular oxygen onto a methyl group, resulting either in a stable hydroxylated product (=hydroxylases) or demethylation of the substrate via oxidative demethylation (=demethylases). The subfamily this proposal addresses are the AlkB-homologs (AlkBHs), which are found in various organisms such as Escherichia coli, Drosophila melanogaster, Schizosaccharomyces pombe, Cenorhabditis elegans and mammals.In mammals there are nine AlkB-homologs known by now: AlkBH1-8 and the fat mass- and obesity-associated gene product (FTO). The differences in sequence, structural elements and accessory domains account for their remarkably large diversity in substrates and biological roles. For individual mammalian AlkBHs it was shown, that loss-off function as well as their aberrant expression and activities can be linked to various diseases phenotypes, such as obesity, severe sensitivity to inflammation, multiple malformations, infertility and cancer, which emphasizes the importance of these enzymes. However, a direct link between the molecular functions, observed phenotype and the substrate scope for many of the human AlkBHs is still unclear. In the here proposed research project our aim is to elucidate the molecular mechanism of the most elusive human AlkBHs. We want to learn about their substrates and interaction network. Our focus will be the human AlkBH1 and AlkBH7 proteins. The employed methods involve cell biology, mass spectrometry and structural biology.

独立于DNA遗传密码，基因和蛋白质活性由表观遗传机制通过写入、阅读和擦除特定的表观遗传标记来控制。这些标记包括组蛋白、DNA和RNA与甲基的共价修饰。这些甲基在许多细胞过程中起着重要作用。负责这些表观遗传标记的空间和时间维护的是所谓的“写入器”和“擦除器”酶。在这里，属于Fe 2 +-和2-酮戊二酸（2 OG; = α-酮戊二酸）依赖性加氧酶家族的酶是特别突出的作用者。迄今为止，已知Fe（II）/2 OG-家族中约有70个成员，分布于所有生命王国。这些酶使用辅助底物2 OG结合亚铁并活化分子氧，以催化分子氧转移到甲基上，从而产生稳定的羟基化产物（=羟化酶）或通过氧化脱甲基作用使底物脱甲基（=脱甲基酶）。AlkB-同系物（AlkBH）是AlkB-同系物的一个亚家族，存在于大肠杆菌、黑腹果蝇、粟酒裂殖酵母、秀丽隐杆线虫和哺乳动物中，目前已知的哺乳动物中有9种AlkB-同系物：AlkBH 1 -8和脂肪量和肥胖相关基因产物（FTO）。它们在序列、结构元件和辅助结构域上的差异导致了它们在底物和生物学作用上的巨大差异。对于个体哺乳动物AlkBH，已经显示，功能丧失以及它们的异常表达和活性可以与各种疾病表型相关，例如肥胖、对炎症的严重敏感性、多发性畸形、不育和癌症，这强调了这些酶的重要性。然而，许多人AlkBH的分子功能、观察到的表型和底物范围之间的直接联系仍不清楚。在这里提出的研究项目中，我们的目标是阐明最难以捉摸的人类AlkBH的分子机制。我们想了解它们的底物和相互作用网络。我们的重点将是人类AlkBH 1和AlkBH 7蛋白。所采用的方法涉及细胞生物学、质谱和结构生物学。