Okanishi Hiroki, Kim Kwang, Masui Ryoji, Kuramitsu Seiki
Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka, 560-0043, Japan.
Department of Tumor Genetics and Biology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan.
Extremophiles. 2017 Mar;21(2):283-296. doi: 10.1007/s00792-016-0901-3. Epub 2016 Dec 7.
Recent studies have revealed the physiological significance of post-translational lysine acylations such as acetylation in the regulation of various cellular processes. Here, we characterized lysine propionylation, a recently discovered post-translational acylation, in five representative bacteria: Geobacillus kaustophilus, Thermus thermophilus, Escherichia coli, Bacillus subtilis, and Rhodothermus marinus. Using antibody-based propionyl peptide enrichment followed by identification with nano-liquid chromatography tandem mass spectrometry, we showed that proteins were subject to lysine propionylation in all five bacterial species analyzed. Notably, many propionylations were identified in the Bacillus-related, thermophilic eubacterium G. kaustophilus, but fewer in the mesophilic eubacterium B. subtilis, suggesting that propionylation event abundance is independent of phylogenetic relationship. We further found propionylation sites in the thermophilic eubacterium T. thermophilus, but the thermophilic eubacterium R. marinus showed the fewest number of sites, indicating that growth temperature is not a determinant of propionylation state. In silico analyses demonstrated that lysine propionylation is related to metabolic pathways, particularly those controlled by acyl-CoA synthetases, similar to lysine acetylation. We also detected dozens of propionylation sites at positions important for protein functions across bacteria, demonstrating the regulatory mechanisms affected by lysine propionylations. Our proteome-wide analyses across bacteria thus provide insights into the general functions of lysine propionylation.
最近的研究揭示了翻译后赖氨酸酰化修饰（如乙酰化）在调控各种细胞过程中的生理意义。在此，我们对赖氨酸丙酰化修饰（一种最近发现的翻译后酰化修饰）在五种代表性细菌中进行了表征，这五种细菌分别是嗜碱栖热菌、嗜热栖热菌、大肠杆菌、枯草芽孢杆菌和海栖热袍菌。通过基于抗体的丙酰化肽富集，随后用纳升液相色谱串联质谱进行鉴定，我们发现所分析的所有五种细菌中的蛋白质都存在赖氨酸丙酰化修饰。值得注意的是，在与芽孢杆菌相关的嗜热真细菌嗜碱栖热菌中鉴定出了许多丙酰化修饰，但在嗜温真细菌枯草芽孢杆菌中较少，这表明丙酰化修饰事件的丰度与系统发育关系无关。我们在嗜热真细菌嗜热栖热菌中进一步发现了丙酰化修饰位点，但嗜热真细菌海栖热袍菌中的位点数量最少，这表明生长温度不是丙酰化修饰状态的决定因素。计算机分析表明，赖氨酸丙酰化修饰与代谢途径有关，特别是那些由酰基辅酶A合成酶控制的代谢途径，这与赖氨酸乙酰化修饰类似。我们还在细菌中对蛋白质功能至关重要的位置检测到了数十个丙酰化修饰位点，证明了赖氨酸丙酰化修饰所影响的调控机制。因此，我们对细菌进行的全蛋白质组分析为赖氨酸丙酰化修饰的一般功能提供了见解。
