Proteomics analyses reveal the evolutionary conservation and divergence of N-terminal acetyltransferases from yeast and humans
Proteomics analyses reveal the evolutionary conservation and divergence of N-terminal acetyltransferases from yeast and humans
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DOI：
10.1073/pnas.0901931106
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发表时间：
2009-05-19
影响因子：
11.1
通讯作者：
Gevaert, Kris
中科院分区：
文献类型：
--
作者：
Arnesen, Thomas;Van Damme, Petra;Gevaert, Kris
N-末端乙酰化是真核生物中最常见的蛋白质修饰之一。利用联合分数对角线层析(COFRADIC)蛋白质组学技术对742个人蛋白和379个酵母蛋白N末端的N末端乙酰化状态进行了研究，得到了N末端乙酰化的最大真核数据集。主要的N末端乙酰基转移酶(NAT)NatA作用于含有丝氨酸、丙氨酸、苏氨酸、甘氨酸、半胱氨酸和Val-N末端的蛋白质亚类。NATA在酵母中由yARD1和yNat1编码的亚基组成，在人类中由hARD1和hNat1编码的亚基组成。一株酵母菌株ard1-Delta Nat1-Delta被hARD1hNat1表型互补，表明yNatA和hNatA相似。然而，异源组合hARD1yNat1和yARD1hNat1在酵母中不具有功能，这表明物种之间存在显著的结构亚基差异。表达hNatA的酵母ard1-Delta Nat1-Delta菌株的蛋白质组学表明，hNatA与yNatA作用于几乎相同的一组酵母蛋白，进一步揭示了来自人和酵母的NatA具有相同或几乎相同的特异性。然而，酵母中的所有NatA底物只有部分N-乙酰化，而HeLa细胞中相应的NatA底物主要是完全N-乙酰化的。总体而言，我们观察到人类N端乙酰化蛋白的比例(84%)高于酵母(57%)。N-乙酰化发生在大约一半的带有Met-Lys末端的人类蛋白质上，但不发生在具有这种末端的酵母蛋白质上。因此，尽管我们在酵母和人类中发现了不同的N-乙酰化模式，但主要的NAT，NatA，在两个物种中产生相同的底物。
N alpha-terminal acetylation is one of the most common protein modifications in eukaryotes. The COmbined FRActional DIagonal Chromatography (COFRADIC) proteomics technology that can be specifically used to isolate N-terminal peptides was used to determine the N-terminal acetylation status of 742 human and 379 yeast protein N termini, representing the largest eukaryotic dataset of N-terminal acetylation. The major N-terminal acetyltransferase (NAT), NatA, acts on subclasses of proteins with Ser-, Ala-, Thr-, Gly-, Cys- and Val- N termini. NatA is composed of subunits encoded by yARD1 and yNAT1 in yeast and hARD1 and hNAT1 in humans. A yeast ard1-Delta nat1-Delta strain was phenotypically complemented by hARD1 hNAT1, suggesting that yNatA and hNatA are similar. However, heterologous combinations, hARD1 yNAT1 and yARD1 hNAT1, were not functional in yeast, suggesting significant structural subunit differences between the species. Proteomics of a yeast ard1-Delta nat1-Delta strain expressing hNatA demonstrated that hNatA acts on nearly the same set of yeast proteins as yNatA, further revealing that NatA from humans and yeast have identical or nearly identical specificities. Nevertheless, all NatA substrates in yeast were only partially N-acetylated, whereas the corresponding NatA substrates in HeLa cells were mainly completely N-acetylated. Overall, we observed a higher proportion of N-terminally acetylated proteins in humans (84%) as compared with yeast (57%). N-acetylation occurred on approximately one-half of the human proteins with Met-Lys-termini, but did not occur on yeast proteins with such termini. Thus, although we revealed different N-acetylation patterns in yeast and humans, the major NAT, NatA, acetylates the same substrates in both species.