Targeted Profiling of Arabidopsis thaliana Subproteomes Illuminates Co- and Posttranslationally N-Terminal Myristoylated Proteins
Targeted Profiling of Arabidopsis thaliana Subproteomes Illuminates Co- and Posttranslationally N-Terminal Myristoylated Proteins
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DOI：
10.1105/tpc.17.00523
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发表时间：
2018-03-01
期刊：
影响因子：
11.6
通讯作者：
Giglione, Carmela
中科院分区：
文献类型：
--
作者：
Majeran, Wojciech;Le Caer, Jean-Pierre;Giglione, Carmela
N-末端豆蔻酰化是真核生物蛋白质的一种重要的脂质修饰，在体内难以检测，并且难以通过计算机模拟进行预测。我们开发了一种蛋白质组学策略，包括细胞膜的亚分级，结合质谱-液相色谱分离疏水肽来鉴定拟南芥淀粉酰化蛋白质组。该方法在所有分析的细胞组分中鉴定了8837种蛋白质的起始池，其占拟南芥蛋白质组的32%。其中，906种蛋白质在2位含有N-末端Gly，这是豆蔻酰化的先决条件，214种属于预测的豆蔻酰组（占421种蛋白质的预测豆蔻酰组的51%）。我们进一步显示了72种蛋白质中豆蔻酰化的直接证据，其中18种豆蔻酰化蛋白质以前没有预测过。我们发现一个豆蔻酰化位点下游的一个预测的起始密码子，表明翻译后豆蔻酰化发生在植物中。超过一半的蛋白质可以被定量并分配到亚细胞区室。结合豆蔻酰化和S-酰化数据的蛋白质积累的层次聚类显示，N-末端双酰化影响重定向到质膜。在少数情况下，MYR功能超出了简单的膜结合。本研究鉴定了数百种N-酰化蛋白质，这些蛋白质的脂质修饰可以控制蛋白质定位并扩展蛋白质功能。
N-terminal myristoylation, a major eukaryotic protein lipid modification, is difficult to detect in vivo and challenging to predict in silico. We developed a proteomics strategy involving subfractionation of cellular membranes, combined with separation of hydrophobic peptides by mass spectrometry-coupled liquid chromatography to identify theArabidopsis thalianamyristoylated proteome. This approach identified a starting pool of 8837 proteins in all analyzed cellular fractions, comprising 32% of the Arabidopsis proteome. Of these, 906 proteins contain an N-terminal Gly at position 2, a prerequisite for myristoylation, and 214 belong to the predicted myristoylome (comprising 51% of the predicted myristoylome of 421 proteins). We further show direct evidence of myristoylation in 72 proteins; 18 of these myristoylated proteins were not previously predicted. We found one myristoylation site downstream of a predicted initiation codon, indicating that posttranslational myristoylation occurs in plants. Over half of the identified proteins could be quantified and assigned to a subcellular compartment. Hierarchical clustering of protein accumulation combined with myristoylation andS-acylation data revealed that N-terminal double acylation influences redirection to the plasma membrane. In a few cases, MYR function extended beyond simple membrane association. This study identified hundreds ofN-acylated proteins for which lipid modifications could control protein localization and expand protein function.