The glycan core of GPI-anchored proteins modulates aerolysin binding but is not sufficient: the polypeptide moiety is required for the toxin-receptor interaction
The glycan core of GPI-anchored proteins modulates aerolysin binding but is not sufficient: the polypeptide moiety is required for the toxin-receptor interaction
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DOI：
10.1016/s0014-5793(02)02274-3
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发表时间：
2002-02-13
期刊：
影响因子：
3.5
通讯作者：
van der Goot, FG
中科院分区：
文献类型：
--
作者：
Abrami, L;Velluz, MC;van der Goot, FG
哺乳动物细胞对细菌毒素气溶素的敏感性是由于其表面存在作为受体的糖基磷脂酰肌醇（GPI）锚定蛋白。使用一组受GPI生物合成途径和布氏锥虫变体表面糖蛋白影响的突变体，我们表明，在聚糖核心的第一个甘露糖上添加磷酸乙醇胺残基不影响结合。相比之下，在该相同甘露糖的位置3处添加多达四个半乳糖残基的侧链导致结合增加。然而，在缺乏将蛋白质转移到预形成的GPI锚的转酰胺酶的突变细胞中积累的无蛋白GPI不能结合毒素，表明需要多肽部分，其性质和大小似乎不太重要，尽管已经鉴定出两个例外。(C)2002年欧洲生物化学学会联合会。由Elsevier Science B.V.出版，版权所有。
Sensitivity of mammalian cells to the bacterial toxin aerolysin is due to the presence at their surface of glycosylphosphatidyl inositol (GPI)-anchored proteins which act as receptors. Using a panel of mutants that are affected in the GPI biosynthetic pathway and Trypanosoma brucei variant surface glycoproteins, we show that addition of an ethanolamine phosphate residue on the first mannose of the glycan core does not affect binding. In contrast, the addition of a side chain of up to four galactose residues at position 3 of this same mannose leads to an increase in binding. However, protein free GPIs, which accumulate in mutant cells deficient in the transamidase that transfers the protein to the pre-formed GPI-anchor, were unable to bind the toxin indicating a requirement for the polypeptide moiety, the nature and size of which seem of little importance although two exceptions have been identified. (C) 2002 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.