N-Glycosylation efficiency is determined by the distance to the C-terminus and the amino acid preceding an Asn-Ser-Thr sequon
N-Glycosylation efficiency is determined by the distance to the C-terminus and the amino acid preceding an Asn-Ser-Thr sequon
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DOI：
10.1002/pro.551
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发表时间：
2011-01-01
期刊：
影响因子：
8
通讯作者：
Mingarro, Ismael
中科院分区：
文献类型：
--
作者：
Bano-Polo, Manuel;Baldin, Francesca;Mingarro, Ismael
n -糖基化是最常见和最通用的蛋白质修饰。在真核细胞中，这种修饰是由寡糖转移酶共翻译催化的，当新生蛋白质进入内质网时，寡糖转移酶靶向新生蛋白质中Asn-Xaa-Ser/Thr一致序列中的天冬酰胺β -酰胺（其中Xaa是除脯氨酸以外的任何氨基酸）。由于膜蛋白上糖基化受体位点的修饰以室特异性的方式发生，糖基化的存在被用来指示膜蛋白的拓扑结构。此外，可以添加糖基化位点以获得拓扑信息。在这项研究中，我们通过在微粒体存在下截断模型蛋白的体外转录/翻译探索了n -糖基化的决定因素，并调查了25,488个糖蛋白，其中2,533个糖基化位点已被实验验证。我们发现糖基化效率取决于到c端的距离和在一致序列之前的氨基酸的性质。这些发现为拓扑学研究中的膜蛋白标记建立了一种广泛适用的方法。
N-glycosylation is the most common and versatile protein modification. In eukaryotic cells, this modification is catalyzed cotranslationally by the enzyme oligosaccharyltransferase, which targets the beta-amide of the asparagine in an Asn-Xaa-Ser/Thr consensus sequon (where Xaa is any amino acid but proline) in nascent proteins as they enter the endoplasmic reticulum. Because modification of the glycosylation acceptor site on membrane proteins occurs in a compartment-specific manner, the presence of glycosylation is used to indicate membrane protein topology. Moreover, glycosylation sites can be added to gain topological information. In this study, we explored the determinants of N-glycosylation with the in vitro transcription/translation of a truncated model protein in the presence of microsomes and surveyed 25,488 glycoproteins, of which 2,533 glycosylation sites had been experimentally validated. We found that glycosylation efficiency was dependent on both the distance to the C-terminus and the nature of the amino acid that preceded the consensus sequon. These findings establish a broadly applicable method for membrane protein tagging in topological studies.