Charbaut Elodie, Redeker Virginie, Rossier Jean, Sobel André
U440 INSERM/UPMC, Institut du Fer à Moulin, 17 rue du Fer à Moulin, 75005 Paris, France.
FEBS Lett. 2002 Oct 9;529(2-3):341-5. doi: 10.1016/s0014-5793(02)03421-x.
N-terminal acetylation is a protein modification common in eukaryotes, but rare in prokaryotes. Here, we characterized five mammalian stathmin-like subdomains expressed in Escherichia coli by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and nanoESI Q-TOF tandem mass spectrometry. We revealed that RB3(SLD) and RB3'(SLD) are N(alpha)-acetylated, whereas SCG10(SLD) and SCLIP(SLD), although identical up to residue 6, are not, as well as stathmin. To assess the influence of the N-terminal sequences on N(alpha)-acetylation, we exchanged residues 7 and 8 between acetylated RB3(SLD) and unacetylated SCG10(SLD), and showed that it reversed the acetylation pattern. Our results demonstrate that ectopic recombinant proteins can be extensively N(alpha)-acetylated in E. coli, and that the rules governing N(alpha)-acetylation are complex and involve the N-terminal region, as in eukaryotes.
N 端乙酰化是真核生物中常见的一种蛋白质修饰，但在原核生物中很少见。在这里，我们通过基质辅助激光解吸/电离飞行时间质谱和纳升电喷雾四极杆飞行时间串联质谱对在大肠杆菌中表达的五个哺乳动物微管相关蛋白样亚结构域进行了表征。我们发现 RB3(SLD) 和 RB3'(SLD) 是 N(α)-乙酰化的，而 SCG10(SLD) 和 SCLIP(SLD)，尽管在第 6 位残基之前是相同的，但与微管相关蛋白一样，不是 N(α)-乙酰化的。为了评估 N 端序列对 N(α)-乙酰化的影响，我们在乙酰化的 RB3(SLD) 和未乙酰化的 SCG10(SLD) 之间交换了第 7 和第 8 位残基，并表明这逆转了乙酰化模式。我们的结果表明，异位重组蛋白在大肠杆菌中可以广泛地进行 N(α)-乙酰化，并且与真核生物一样，控制 N(α)-乙酰化的规则很复杂，并且涉及 N 端区域。
