College of Food Science and Technology, Hunan Agricultural University, Changsha, Hunan 410128, China.
Nanya Middle School, Changsha, Hunan 410129, China.
J Proteomics. 2019 Aug 15;205:103412. doi: 10.1016/j.jprot.2019.103412. Epub 2019 Jun 6.
Protein lysine acetylation is an post-translational modification that regulates gene expression, metabolism, cell signaling, and diseases, but its implication in the postmortem (PM) meat quality development is basically unclear. In the present study, a quantitative proteomic analysis was conducted to profile acetylome in porcine muscle within 24 h PM. In total 595 acetylation sites assigned to 163 proteins were identified in porcine muscle, of which 460 sites distributing to 110 proteins significantly changed in acetylation levels in the conversion of muscle to meat. The dynamic acetylation/deacetylaion of muscle proteins was closely associated with critical chemical-biophysical changes in PM muscle. Bioinformatic analysis revealed that protein lysine acetylation likely regulated postmortem meat quality development by regulating glycolysis and muscle pH, cell stress reponse and apoptosis, muscle contraction and rigor mortis, calcium signaling and proteolysis, IMP synthesis and meat flavor development, and even the stability of pigment proteins and meat color. This study provided the first overview of protein lysine acetylation in PM muscle and revealed its significance in the conversion of muscle to meat. Future exploration of the exact role of protein lysine acetylation at specific sites will further our understanding regarding the underlying mechanisms and be helpful for meat quality control. SIGNIFICANCE: This is the first analysis of acetylome in farm animal and postmortem muscle. Our data showed that the dynamic acetylation/deacetylation of muscle proteins was closely related to the postmortem changes of muscle that affect the final quality of raw meat. Proteins related to glucose metabolism and muscle contraction were the two largest clusters of acetylproteins identified in postmortem porcine muscle. Networks of acetylproteins involved in apoptosis, calcium signaling and IMP synthesis were identified in postmortem porcine muscle at the same time. Our results revealed that protein lysine acetylation regulated the conversion of muscle to meat. It likely regulated meat quality development by regulating postmortem glycolysis, mitochondrion initiated cell apoptosis, calcium signaling, rigor mortis, meat flavor compound sysnthesis and meat tenderization. Our study broadened our understanding of the biochemistry regulating the postmortem conversion of muscle to meat and final meat quality development, which may be helpful for future meat quality control.
蛋白质赖氨酸乙酰化是一种翻译后修饰，可调节基因表达、代谢、细胞信号转导和疾病，但它在死后（PM）肉质发展中的影响基本不清楚。在本研究中，进行了定量蛋白质组学分析，以描绘 PM 后 24 小时内猪肌肉中的乙酰组。总共鉴定了 595 个分配给 163 种蛋白质的乙酰化位点，其中 460 个分布在肌肉向肉转化过程中乙酰化水平发生显著变化的蛋白质中。肌肉蛋白的动态乙酰化/去乙酰化与 PM 肌肉中关键的化学-生物物理变化密切相关。生物信息学分析表明，蛋白质赖氨酸乙酰化可能通过调节糖酵解和肌肉 pH 值、细胞应激反应和细胞凋亡、肌肉收缩和僵直、钙信号转导和蛋白水解、IMP 合成和肉味发展、甚至色素蛋白和肉色的稳定性来调节死后肉质的发展。本研究首次概述了 PM 肌肉中的蛋白质赖氨酸乙酰化，并揭示了其在肌肉向肉转化中的意义。未来对特定位点蛋白质赖氨酸乙酰化的确切作用的探索将进一步加深我们对潜在机制的理解，并有助于控制肉质。意义：这是首次对农场动物和死后肌肉中的乙酰组进行分析。我们的数据表明，肌肉蛋白的动态乙酰化/去乙酰化与影响生肉最终质量的肌肉死后变化密切相关。与葡萄糖代谢和肌肉收缩相关的蛋白质是鉴定的死后猪肌肉中两个最大的乙酰蛋白簇。同时，还鉴定了死后猪肌肉中涉及细胞凋亡、钙信号转导和 IMP 合成的乙酰蛋白网络。我们的结果表明，蛋白质赖氨酸乙酰化调节肌肉向肉的转化。它可能通过调节死后糖酵解、线粒体启动的细胞凋亡、钙信号转导、僵直、肉味化合物合成和肉嫩化来调节肉质的发展。我们的研究拓宽了我们对调节肌肉死后转化和最终肉质发展的生化的理解，这可能有助于未来的肉质控制。
