Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom.
PLoS Biol. 2011 May;9(5):e1001073. doi: 10.1371/journal.pbio.1001073. Epub 2011 May 31.
Amino-terminal acetylation is probably the most common protein modification in eukaryotes with as many as 50%-80% of proteins reportedly altered in this way. Here we report a systematic analysis of the predicted N-terminal processing of cytosolic proteins versus those destined to be sorted to the secretory pathway. While cytosolic proteins were profoundly biased in favour of processing, we found an equal and opposite bias against such modification for secretory proteins. Mutations in secretory signal sequences that led to their acetylation resulted in mis-sorting to the cytosol in a manner that was dependent upon the N-terminal processing machinery. Hence N-terminal acetylation represents an early determining step in the cellular sorting of nascent polypeptides that appears to be conserved across a wide range of species.
氨基末端乙酰化可能是真核生物中最常见的蛋白质修饰方式，据报道多达 50%-80%的蛋白质都以这种方式发生改变。在这里，我们报告了对细胞质蛋白和分泌途径蛋白的预测 N 端加工的系统分析。虽然细胞质蛋白在加工方面存在明显的倾向性，但我们发现分泌蛋白的这种修饰存在同等且相反的倾向性。导致其乙酰化的分泌信号序列突变会导致它们以依赖于 N 端加工机制的方式错误地分选到细胞质中。因此，N 端乙酰化代表了新生多肽在细胞分选过程中的早期决定步骤，这种现象似乎在广泛的物种中都得到了保守。
