Fusion-competent state induced by a C-terminal HIV-1 fusion peptide in cholesterol-rich membranes
Fusion-competent state induced by a C-terminal HIV-1 fusion peptide in cholesterol-rich membranes
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DOI：
10.1016/j.bbamem.2015.01.011
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发表时间：
2015-04-01
影响因子：
3.4
通讯作者：
Nieva, Jose L.
中科院分区：
文献类型：
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作者：
Apellaniz, Beatriz;Nieva, Jose L.
人类免疫缺陷病毒1型的复制周期在病毒和靶细胞膜融合后开始。囊膜糖蛋白gp41跨膜亚单位含有保守的疏水结构域，参与并干扰合并的脂双层。在这项工作中，我们表征了CpreTM在囊泡中产生的融合承诺状态，CpreTM是一种合成肽，来自连接gp41的膜近端外部区域(MPER)和跨膜结构域(TMD)的序列。用CpreTM预载载高胆固醇的囊泡，使它们能够与荧光标记的目标囊泡进行随后的脂质混合。突显持久融合能力状态的生理相关性的是，广谱中和抗体4E10与CpreTM启动的囊泡结合并抑制脂质混合。异型融合分析揭示了对充当病毒或细胞膜替代物的囊泡的脂组成的依赖。在这些实验中，脂肪混合首先表现出对胆固醇含量的关键依赖。我们推断，这里描述的融合能力状态类似于病毒膜内的前发夹MPER-TMD连接所产生的真正的扰动。(C)2015爱思唯尔B.V.保留所有权利。
The replicative cycle of the human immunodeficiency virus type-1 begins after fusion of the viral and target-cell membranes. The envelope glycoprotein gp41 transmembrane subunit contains conserved hydrophobic domains that engage and perturb the merging lipid bilayers. In this work, we have characterized the fusion-committed state generated in vesicles by CpreTM, a synthetic peptide derived from the sequence connecting the membrane-proximal external region (MPER) and the transmembrane domain (TMD) of gp41. Pre-loading cholesterol-rich vesicles with CpreTM rendered them competent for subsequent lipid-mixing with fluorescently-labeled target vesicles. Highlighting the physiological relevance of the lasting fusion-competent state, the broadly neutralizing antibody 4E10 bound to the CpreTM-primed vesicles and inhibited lipid-mixing. Heterotypic fusion assays disclosed dependence on the lipid composition of the vesicles that acted either as virus or cell membrane surrogates. Lipid-mixing exhibited above all a critical dependence on the cholesterol content in those experiments. We infer that the fusion-competent state described herein resembles bona-fide perturbations generated by the pre-hairpin MPER-TMD connection within the viral membrane. (C) 2015 Elsevier B.V. All rights reserved.