Ministry of Education Key Laboratory of Bioinformatics, Centre for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
Center for Synthetic Biology Engineering Research, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
Proc Natl Acad Sci U S A. 2017 Aug 15;114(33):8782-8787. doi: 10.1073/pnas.1700796114. Epub 2017 Aug 2.
New types of modifications of histones keep emerging. Recently, histone H4K8 2-hydroxyisobutyrylation (H4K8) was identified as an evolutionarily conserved modification. However, how this modification is regulated within a cell is still elusive, and the enzymes adding and removing 2-hydroxyisobutyrylation have not been found. Here, we report that the amount of H4K8 fluctuates in response to the availability of carbon source in and that low-glucose conditions lead to diminished modification. The removal of the 2-hydroxyisobutyryl group from H4K8 is mediated by the histone lysine deacetylase Rpd3p and Hos3p in vivo. In addition, eliminating modifications at this site by alanine substitution alters transcription in carbon transport/metabolism genes and results in a reduced chronological life span (CLS). Furthermore, consistent with the glucose-responsive H4K8 regulation, proteomic analysis revealed that a large set of proteins involved in glycolysis/gluconeogenesis are modified by lysine 2-hydroxyisobutyrylation. Cumulatively, these results established a functional and regulatory network among K, glucose metabolism, and CLS.
新的组蛋白修饰类型不断涌现。最近,组蛋白 H4K8 2-羟基异丁酰化(H4K8)被鉴定为一种进化上保守的修饰。然而,这种修饰在细胞内是如何被调控的仍然难以捉摸,并且还没有发现添加和去除 2-羟基异丁酰化的酶。在这里,我们报告说 H4K8 的含量会根据 的碳源可用性而波动,并且低葡萄糖条件会导致修饰减少。H4K8 上 2-羟基异丁酰基的去除是由组蛋白赖氨酸去乙酰化酶 Rpd3p 和 Hos3p 在体内介导的。此外,通过丙氨酸取代消除该位点的修饰会改变碳转运/代谢基因的转录,并导致细胞程序性死亡(CLS)缩短。此外,与葡萄糖响应的 H4K8 调控一致,蛋白质组学分析表明,大量参与糖酵解/糖异生的蛋白质被赖氨酸 2-羟基异丁酰化修饰。总之,这些结果建立了 K、葡萄糖代谢和 CLS 之间的功能和调控网络。