Structural peptides of a nonenveloped virus are involved in assembly and membrane translocation
Structural peptides of a nonenveloped virus are involved in assembly and membrane translocation
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DOI：
10.1128/jvi.79.19.12253-12263.2005
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发表时间：
2005-10-01
影响因子：
5.4
通讯作者：
Delmas, B
中科院分区：
文献类型：
--
作者：
Chevalier, C;Galloux, M;Delmas, B
传染性法氏囊病病毒（IBDV）是伯纳病毒科的一种非包膜病毒，其衣壳具有T=131的二十面体外壳，由单个蛋白VP2和一些无序肽组成，它们都来源于前体pVP2。在这项研究中，我们发现两种肽，pep11和pep46，控制病毒组装和细胞进入。pep11的缺失或其大部分残基的简单替换都会阻断衣壳的形态发生。去除pep46也会阻止衣壳组装，但会导致由未加工的VP2物种形成的亚病毒颗粒的形成。将VP2原子模型拟合到这些粒子的三维重建中，表明未裂解pep46的存在在顶点处引起空间位阻，阻止了五重轴的形成。pVP2成熟位点的突变证实了C端加工对于VP2获得正确的二十面体结构是必要的。所有存在于病毒粒子上的肽都是。可用于蛋白酶或生化标记。其中之一，pep46，已被证明在脂质体中诱导大的结构重排并破坏靶膜的稳定，这表明它在细胞进入过程中具有重要意义。
The capsid of infectious bursal disease virus (IBDV), a nonenveloped virus of the family Birnaviridae, has a T=131 icosahedral shell constituted by a single protein, VP2, and several disordered peptides, all derived from the precursor pVP2. In this study, we show that two of the peptides, pep11 and pep46, control virus assembly and cell entry. Deletion of pep11 or even simple substitution of most of its residues blocks the capsid morphogenesis. Removal of pep46 also prevents capsid assembly but leads to the formation of subviral particles formed by unprocessed VP2 species. Fitting with the VP2 atomic model into three-dimensional reconstructions of these particles demonstrates that the presence of uncleaved pep46 causes a steric hindrance at the vertices, blocking fivefold axis formation. Mutagenesis of the pVP2 maturation sites confirms that C terminus processing is necessary for VP2 to acquire the correct icosahedral architecture. All peptides present on virions are. accessible to proteases or biochemical labeling. One of them, pep46, is shown to induce large structural rearrangements in liposomes and to destabilize target membranes, demonstrating its implication in cell entry.