Structural analysis of hepatitis C virus core-E1 signal peptide and requirements for cleavage of the genotype 3a signal sequence by signal peptide peptidase.
Structural analysis of hepatitis C virus core-E1 signal peptide and requirements for cleavage of the genotype 3a signal sequence by signal peptide peptidase.
复制标题
丙型肝炎病毒核心E1信号肽的结构分析及信号肽肽酶切割基因型3a信号序列的要求。
DOI：
10.1128/jvi.00457-12
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发表时间：
2012
影响因子：
5.4
通讯作者：
Oehler V
中科院分区：
文献类型：
--
作者：
Oehler V
丙型肝炎病毒（HCV）核心蛋白的成熟需要两种宿主蛋白酶的蛋白水解加工：信号肽酶（SP）和膜内裂解蛋白酶信号肽肽酶（SPP）。先前对HCV基因型1a（GT 1a）和GT 2a的研究已经确定了SPP有效加工信号肽所需的关键残基，这反过来又对感染性病毒颗粒的产生影响。在这里，我们证明了JFH 1 GT 2a核心-E1信号肽可以适应GT 3a序列，而不会影响传染性HCV的产生。通过诱变研究，我们确定了核心E1信号肽加工所需的关键残基，包括位置187处的GT 3a序列特异性组氨酸（His）。此外，HuH-7细胞中胞内SPP水平的稳定敲低显著影响HCV病毒滴度，进一步证明了核心成熟和感染性HCV颗粒产生对SPP的需求。最后，我们的核磁共振（NMR）的合成HCV JFH 1 GT 2a核心-E1信号肽的结构分析提供了一个必要的结构模板，为进一步了解核心加工以及SPP基板在其膜环境中的第一个模型。我们的发现为膜内裂解蛋白酶的机制以及对病毒感染的影响提供了更深入的见解。
The maturation of the hepatitis C virus (HCV) core protein requires proteolytic processing by two host proteases: signal peptidase (SP) and the intramembrane-cleaving protease signal peptide peptidase (SPP). Previous work on HCV genotype 1a (GT1a) and GT2a has identified crucial residues required for efficient signal peptide processing by SPP, which in turn has an effect on the production of infectious virus particles. Here we demonstrate that the JFH1 GT2a core-E1 signal peptide can be adapted to the GT3a sequence without affecting the production of infectious HCV. Through mutagenesis studies, we identified crucial residues required for core-E1 signal peptide processing, including a GT3a sequence-specific histidine (His) at position 187. In addition, the stable knockdown of intracellular SPP levels in HuH-7 cells significantly affects HCV virus titers, further demonstrating the requirement for SPP for the maturation of core and the production of infectious HCV particles. Finally, our nuclear magnetic resonance (NMR) structural analysis of a synthetic HCV JFH1 GT2a core-E1 signal peptide provides an essential structural template for a further understanding of core processing as well as the first model for an SPP substrate within its membrane environment. Our findings give deeper insights into the mechanisms of intramembrane-cleaving proteases and the impact on viral infections.