蛋白翻譯後修飾對蛋白質的結構和功能起著關鍵作用,是細胞精細調節生理活動的關鍵之一。因而,蛋白翻譯後修飾通路研究是目前新藥研發的重要熱點之一。
中科院上海藥物研究所化學蛋白質組學研究中心與美國芝加哥大學、密西根大學合作研究,首次在哺乳動物細胞中對去乙醯化調控酶Sirt5調控的琥珀醯底物進行了系統的蛋白質組學研究,在779個蛋白上鑑定出2500多個琥珀醯位點。此項研究通過綜合運用生物質譜、生物化學和生物信息學方法,證明琥珀醯化廣泛存在於線粒體能量代謝調控酶中,參與調控包括三羧酸循環、胺基酸代謝以及脂肪酸代謝在內的多個代謝信號通路。同時也發現,琥珀醯化存在於細胞漿和細胞核蛋白中,並揭示了琥珀醯化能抑制丙酮酸脫氫酶和琥珀酸脫氫酶複合物活性。此項研究揭示了蛋白琥珀醯修飾具有廣泛調節細胞代謝的作用,同時也提示此修飾可能影響其它重要細胞生物學功能。
這是化學蛋白質組學研究中心繼首次發現賴氨酸去琥珀醯和去丙二醯兩種新翻譯後修飾通路,並首次揭示去乙醯化酶Sirt5實為賴氨酸去琥珀醯和丙二醯化的調控酶之後的又一重要研究突破。首次系統性揭示了受賴氨酸去乙醯化酶(HDACs)Sirt5調控的琥珀醯化底物蛋白,發現了琥珀醯化修飾對能量代謝中的關鍵酶的調控作用,進一步明確了Sirt5的去琥珀醯化作用的生物學意義,並為Sirt5的生物學和新藥研究提供了重要資源。
相關研究工作上海藥物所以共同通訊作者單位於6月27日發表在最新一期的國際期刊Molecular Cell雜誌上。(生物谷Bioon.com)
SIRT5-Mediated Lysine Desuccinylation Impacts Diverse Metabolic Pathways
Jeongsoon Park, Yue Chen, Daniel X. Tishkoff, Chao Peng, Minjia Tan, Lunzhai Dai, Zhongyu Xie, Yi Zhang, Bernadette M.M. Zwaans, Mary E. Skinner, David B. Lombard, Yingming Zhao
Protein function is regulated by diverse posttranslational modifications. The mitochondrial sirtuin SIRT5 removes malonyl and succinyl moieties from target lysines. The spectrum of protein substrates subject to these modifications is unknown. We report systematic profiling of the mammalian succinylome, identifying 2,565 succinylation sites on 779 proteins. Most of these do not overlap with acetylation sites, suggesting differential regulation of succinylation and acetylation. Our analysis reveals potential impacts of lysine succinylation on enzymes involved in mitochondrial metabolism; e.g., amino acid degradation, the tricarboxylic acid cycle (TCA) cycle, and fatty acid metabolism. Lysine succinylation is also present on cytosolic and nuclear proteins; indeed, we show that a substantial fraction of SIRT5 is extramitochondrial. SIRT5 represses biochemical activity of, and cellular respiration through, two protein complexes identified in our analysis, pyruvate dehydrogenase complex and succinate dehydrogenase. Our data reveal widespread roles for lysine succinylation in regulating metabolism and potentially other cellular functions.