【作者】 王科云； 周雍进； 刘宏伟； 邹汉法； 赵宗保；

【Author】 Keyun Wang;Yongjin Zhou;Hongwei Liu;Hanfa Zou;Zongbao K. Zhao;Dalian Institute of Chemical Physics;

【机构】 中国科学院大连化学物理研究所；

【摘要】 腺苷甲硫氨酸(SAM)依赖型蛋白质甲基化是一种重要的翻译后修饰现象。由于甲基化可以发生在N-,O-和S-中心,并且在N-中心甲基化还存在不同状态,人们对甲基化蛋白质组了解得还很不深入。一些非常有挑战性问题至今没有答案,如,蛋白质组甲基化程度如何.蛋白质甲基化的氨基酸选择性如何.蛋白质N-甲基化状态分布如何.为回答这些问题,我们构建了SAM-营养缺陷型酿酒酵母菌株,设计同位素标记SAM的甲基化策略结合在线多维μHPLC/MS/MS技术实现了对酿酒酵母甲基化蛋白质组的高可信度分析。鉴定了73个甲基化蛋白,包括分布在109个甲基化中心的113个甲基化事件,其中超过95%的甲基化事件是首次发现。这是迄今为止最全面的酵母蛋白质甲基化组数据。分析表明,1)超过4%的酵母蛋白质存在甲基化;2)甲基化发生在氨基酸残基的顺序为Lys>>Arg>Asp>Glu≈Asp≈Gln≈His>Cys;3)N-甲基化状态存在一定的互斥性。研究结果极大地丰富了对蛋白质甲基化的科学认识。更多还原

【Abstract】 Protein methylation catalyzed by SAM-dependent methyltransferase represents a major PTM involved in important biological processes. Because methylation can occur on nitrogen, oxygen and sulfur centres and multiple methylation states exist on the nitrogen centres, methylproteome remains poorly documented. Several fundamental questions in the field remain unanswered. For example, to what extent a proteome is methylated? Are there anypreferences among different methylation centers or amino acid residues? In the case of methylation on nitrogen centre, what is the distribution profile for different methylation states? To address those questions, we engineered SAM-auxotrophic Saccharomyces cerevisiae strain, and designed the methylation by isotope labelled SAM(MILS) strategy for a highly-confident analysis of the yeast methylproteome based on the online multidimensional μHPLC/MS/MS technology. We identified 73 methylated proteins, containing 113 methylation events associated with 109 methylation sites. More than 95% of these methylation events were previously unannotated in the Uniprot database. Our results indicated, 1) over 4 % of yeast proteins are methylated, 2) the amino acid residue preference of protein methylation follows the order Lys >> Arg > Asp > Glu ≈ Asp ≈ Gln ≈ His > Cys, 3) the methylation state on nitrogen center is largely exclusive. Our dataset is the most comprehensive methylproteome known-to-date for S. cerevisiae, and should significantly contribute to the field of protein methylation and related research.更多还原