Castaño-Cerezo Sara, Bernal Vicente, Post Harm, Fuhrer Tobias, Cappadona Salvatore, Sánchez-Díaz Nerea C, Sauer Uwe, Heck Albert J R, Altelaar A F Maarten, Cánovas Manuel
Departamento de Bioquímica y Biología Molecular B e Inmunología, Facultad de Química, Universidad de Murcia Campus de Excelencia Mare Nostrum, Murcia, Spain.
Departamento de Bioquímica y Biología Molecular B e Inmunología, Facultad de Química, Universidad de Murcia Campus de Excelencia Mare Nostrum, Murcia, Spain
Mol Syst Biol. 2014 Nov 27;10(11):762. doi: 10.15252/msb.20145227.
Although protein acetylation is widely observed, it has been associated with few specific regulatory functions making it poorly understood. To interrogate its functionality, we analyzed the acetylome in Escherichia coli knockout mutants of cobB, the only known sirtuin-like deacetylase, and patZ, the best-known protein acetyltransferase. For four growth conditions, more than 2,000 unique acetylated peptides, belonging to 809 proteins, were identified and differentially quantified. Nearly 65% of these proteins are related to metabolism. The global activity of CobB contributes to the deacetylation of a large number of substrates and has a major impact on physiology. Apart from the regulation of acetyl-CoA synthetase, we found that CobB-controlled acetylation of isocitrate lyase contributes to the fine-tuning of the glyoxylate shunt. Acetylation of the transcription factor RcsB prevents DNA binding, activating flagella biosynthesis and motility, and increases acid stress susceptibility. Surprisingly, deletion of patZ increased acetylation in acetate cultures, which suggests that it regulates the levels of acetylating agents. The results presented offer new insights into functional roles of protein acetylation in metabolic fitness and global cell regulation.
尽管蛋白质乙酰化现象广泛存在，但其与特定调控功能的关联却很少，这使得人们对其了解甚少。为了探究其功能，我们分析了大肠杆菌中cobB（唯一已知的类沉默调节蛋白去乙酰化酶）和patZ（最著名的蛋白质乙酰转移酶）基因敲除突变体的乙酰化蛋白质组。针对四种生长条件，我们鉴定并差异定量了属于809种蛋白质的2000多种独特的乙酰化肽段。这些蛋白质中近65%与代谢相关。CobB的全局活性有助于大量底物的去乙酰化，并对生理过程产生重大影响。除了对乙酰辅酶A合成酶的调控外，我们发现CobB控制的异柠檬酸裂解酶乙酰化有助于乙醛酸循环的微调。转录因子RcsB的乙酰化会阻止其与DNA结合，激活鞭毛生物合成和运动能力，并增加对酸胁迫的敏感性。令人惊讶的是，patZ的缺失增加了乙酸盐培养物中的乙酰化水平，这表明它调节乙酰化剂的水平。本文给出的结果为蛋白质乙酰化在代谢适应性和全局细胞调控中的功能作用提供了新的见解。
