Proteomic Analysis Reveals Diverse Classes of Arginine Methylproteins in Mitochondria of Trypanosomes
Proteomic Analysis Reveals Diverse Classes of Arginine Methylproteins in Mitochondria of Trypanosomes
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DOI：
10.1074/mcp.m112.022533
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发表时间：
2013-02-01
影响因子：
7
通讯作者：
Read, Laurie K.
中科院分区：
文献类型：
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作者：
Fisk, John C.;Li, Jun;Read, Laurie K.
精氨酸 (arg) 甲基化是一种广泛存在的蛋白质翻译后修饰，会影响许多细胞过程，例如染色质重塑、RNA 加工、DNA 修复和细胞信号传导。已知的精氨酸甲基蛋白主要来自酵母和哺乳动物，并且几乎完全是细胞核和细胞质中的。布氏锥虫是一种早期分支真核生物，其基因组编码五种推定的蛋白质精氨酸甲基转移酶，因此可能含有过多的精氨酸甲基蛋白。此外，锥虫和相关生物体拥有独特的线粒体，该线粒体经历剧烈的发育调节，并使用新颖的 RNA 编辑和线粒体 DNA 复制机制。在这里，我们对布氏锥虫线粒体进行了全局质谱分析，以鉴定这种医学相关寄生虫中新的 arg 甲基蛋白。这项工作的促成因素是使用两种正交酶的组合消化、高效的离线二维色谱分离以及具有两种互补激活的高分辨率质谱分析。这种方法使得在蛋白质组水平上对甲基精氨酸进行了全面、灵敏且可靠的鉴定和定位。我们鉴定了 167 种具有广泛功能的 arg 甲基蛋白，包括代谢、运输、陪伴、RNA 加工、翻译和 DNA 复制。我们的数据表明，锥虫线粒体中的 arg 甲基蛋白同时具有锥虫特异性和进化保守的修饰，具体取决于目标蛋白质。这项研究是对任何生物体中线粒体 arg 甲基化的首次全面分析，代表了我们对 arg 甲基蛋白范围及其修饰位点的了解的重大进步。此外，这些研究将布氏锥虫确立为研究翻译后修饰的模式生物。分子与细胞蛋白质组学 12: 10.1074/mcp.M112.022533, 302-311, 2013。
Arginine (arg) methylation is a widespread posttranslational modification of proteins that impacts numerous cellular processes such as chromatin remodeling, RNA processing, DNA repair, and cell signaling. Known arg methylproteins arise mostly from yeast and mammals, and are almost exclusively nuclear and cytoplasmic. Trypanosoma brucei is an early branching eukaryote whose genome encodes five putative protein arg methyltransferases, and thus likely contains a plethora of arg methylproteins. Additionally, trypanosomes and related organisms possess a unique mitochondrion that undergoes dramatic developmental regulation and uses novel RNA editing and mitochondrial DNA replication mechanisms. Here, we performed a global mass spectrometric analysis of the T. brucei mitochondrion to identify new arg methylproteins in this medically relevant parasite. Enabling factors of this work are use of a combination digestion with two orthogonal enzymes, an efficient offline two dimensional chromatography separation, and high-resolution mass spectrometry analysis with two complementary activations. This approach led to the comprehensive, sensitive and confident identification and localization of methylarg at a proteome level. We identified 167 arg methylproteins with wide-ranging functions including metabolism, transport, chaperoning, RNA processing, translation, and DNA replication. Our data suggest that arg methylproteins in trypanosome mitochondria possess both trypanosome-specific and evolutionarily conserved modifications, depending on the protein targeted. This study is the first comprehensive analysis of mitochondrial arg methylation in any organism, and represents a significant advance in our knowledge of the range of arg methylproteins and their sites of modification. Moreover, these studies establish T. brucei as a model organism for the study of posttranslational modifications. Molecular & Cellular Proteomics 12: 10.1074/mcp.M112.022533, 302-311, 2013.