State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences , Beijing 100101, China.
Core Facility of Institute of Microbiology, Chinese Academy of Sciences , Beijing 100101, China.
J Proteome Res. 2017 Sep 1;16(9):3229-3241. doi: 10.1021/acs.jproteome.7b00222. Epub 2017 Aug 22.
Lysine acetylation is a reversible and highly regulated post-translational modification that plays a critical role in regulating many aspects of cellular processes, both in bacteria and in eukaryotes. However, this modification has not been systematically studied in archaea. Herein, we report the lysine acetylome of a model haloarchaeon, Haloferax mediterranei. Using immunoaffinity enrichment and LC-MS/MS analysis, we identified 1017 acetylation sites in 643 proteins, accounting for 17.3% of the total proteins in this haloarchaeon. Bioinformatics analysis indicated that lysine acetylation mainly distributes in cytoplasm (94%) and participates in protein biosynthesis and carbon metabolism. Specifically, the acetylation of key enzymes in PHBV biosynthesis further suggested that acetylation plays a key role in the energy and carbon storage. In addition, a survey of the acetylome revealed a universal rule in acetylated motifs: a positively charged residue (K, R, or H) located downstream of acetylated lysine at the positions +1, +2, or +3. Interestingly, we identified acetylation in several replication initiation proteins Cdc6; mutation on the acetylated site of Cdc6A destroyed the Autonomous Replication Sequence (ARS) activity of its adjacent origin oriC1. Our study indicates that lysine acetylation is an abundant modification in H. mediterranei, and plays key roles in the processes of replication, protein biosynthesis, central metabolism, and carbon storage. This acetylome of H. mediterranei provides opportunities to explore the physiological role of acetylation in halophilic archaea.
赖氨酸乙酰化是一种可逆且高度调控的翻译后修饰，在调节细菌和真核生物中许多细胞过程方面起着关键作用。然而，这种修饰在古菌中尚未得到系统研究。在此，我们报告了模式嗜盐古菌盐沼盐杆菌的赖氨酸乙酰组。通过免疫亲和富集和 LC-MS/MS 分析，我们在 643 种蛋白质中鉴定出 1017 个乙酰化位点，占该嗜盐古菌总蛋白质的 17.3%。生物信息学分析表明，赖氨酸乙酰化主要分布在细胞质中（94%），参与蛋白质生物合成和碳代谢。具体来说，PHBV 生物合成关键酶的乙酰化进一步表明，乙酰化在能量和碳储存中起着关键作用。此外，乙酰组的调查揭示了乙酰化基序的一个普遍规则：位于乙酰化赖氨酸后第+1、+2 或+3 位的带正电荷的残基（K、R 或 H）。有趣的是，我们在几个复制起始蛋白 Cdc6 中鉴定出了乙酰化，Cdc6A 上乙酰化位点的突变破坏了其相邻起始原点 oriC1 的自主复制序列 (ARS) 活性。我们的研究表明，赖氨酸乙酰化是盐沼盐杆菌中丰富的修饰，在复制、蛋白质生物合成、中心代谢和碳储存过程中发挥关键作用。该盐沼盐杆菌的乙酰组为探索乙酰化在嗜盐古菌中的生理作用提供了机会。
