A Leucine Residue in the C Terminus of Human Parainfluenza Virus Type 3 Matrix Protein Is Essential for Efficient Virus-Like Particle and Virion Release
A Leucine Residue in the C Terminus of Human Parainfluenza Virus Type 3 Matrix Protein Is Essential for Efficient Virus-Like Particle and Virion Release
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DOI：
10.1128/jvi.01485-14
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发表时间：
2014-11-01
影响因子：
5.4
通讯作者：
Chen, Mingzhou
中科院分区：
文献类型：
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作者：
Zhang, Guangyuan;Zhang, Shengwei;Chen, Mingzhou
副粘病毒颗粒，像其他包膜病毒颗粒一样，通过从感染细胞的膜出芽而形成，并且基质（M）蛋白对于该过程至关重要。为了鉴定对这一过程重要的M蛋白，我们已经表征了人副流感病毒3型（HPIV 3）M蛋白的出芽。我们的结果表明，单独表达HPIV 3 M蛋白足以启动病毒样颗粒（VLP）的释放。电子显微镜分析证实VLP在形态上与HPIV 3病毒粒子相似。我们鉴定了HPIV 3 M蛋白C末端的亮氨酸（L302）残基，其通过调节M蛋白的泛素化对M蛋白介导的VLP产生至关重要。当L302突变为A302时，M蛋白的泛素化缺陷，VLP的释放被取消，M蛋白的膜结合和出芽能力大大减弱，但M-L302 A突变体保留了寡聚化活性，并对M蛋白介导的VLP产生具有显性负效应。此外，用蛋白酶体抑制剂治疗也抑制M蛋白介导的VLP产生和病毒出芽。最后，不能拯救含有M-L302 A突变体的重组HPIV 3。这些结果表明L302作为一个关键的调节信号的泛素化HPIV 3 M蛋白和病毒粒子的释放。重要提示人副流感病毒3型（HPIV 3）是一种包膜病毒与非节段负链RNA基因组。它可以引起严重的呼吸道疾病，如细支气管炎，肺炎和婴儿和幼儿的哮吼。然而，目前还没有有效的抗病毒治疗或疫苗。因此，进一步阐明其组装和出芽将有助于开发新的治疗方法。在这里，我们表明，亮氨酸残基（L302）位于C末端的HPIV 3 M蛋白是必不可少的有效生产的病毒样颗粒（VLP）。此外，我们发现L302通过调节M蛋白泛素化来调节M蛋白介导的VLP产生。含有M-L302 A突变体的重组HPIV 3具有生长缺陷。这些发现为M蛋白介导的VLP产生和病毒体释放不属于L结构域的残基的关键作用提供了新的见解，并可能促进我们对HPIV 3病毒组装和出芽的理解。
Paramyxovirus particles, like other enveloped virus particles, are formed by budding from membranes of infected cells, and matrix (M) proteins are critical for this process. To identify the M protein important for this process, we have characterized the budding of the human parainfluenza virus type 3 (HPIV3) M protein. Our results showed that expression of the HPIV3 M protein alone is sufficient to initiate the release of virus-like particles (VLPs). Electron microscopy analysis confirmed that VLPs are morphologically similar to HPIV3 virions. We identified a leucine (L302) residue within the C terminus of the HPIV3 M protein that is critical for M protein-mediated VLP production by regulating the ubiquitination of the M protein. When L302 was mutated into A302, ubiquitination of M protein was defective, the release of VLPs was abolished, and the membrane binding and budding abilities of M protein were greatly weakened, but the M-L302A mutant retained oligomerization activity and had a dominant negative effect on M protein-mediated VLP production. Furthermore, treatment with a proteasome inhibitor also inhibited M protein-mediated VLP production and viral budding. Finally, recombinant HPIV3 containing the M-L302A mutant could not be rescued. These results suggest that L302 acts as a critical regulating signal for the ubiquitination of the HPIV3 M protein and virion release.IMPORTANCEHuman parainfluenza virus type 3 (HPIV3) is an enveloped virus with a non segmented negative-strand RNA genome. It can cause severe respiratory tract diseases, such as bronchiolitis, pneumonia, and croup in infants and young children. However, no valid antiviral therapy or vaccine is currently available. Thus, further elucidation of its assembly and budding will be helpful in the development of novel therapeutic approaches. Here, we show that a leucine residue (L302) located at the C terminus of the HPIV3 M protein is essential for efficient production of virus-like particles (VLPs). Furthermore, we found L302 regulated M protein-mediated VLP production via regulation of M protein ubiquitination. Recombinant HPIV3 containing the M-L302A mutant is growth defective. These findings provide new insight into the critical role of M protein-mediated VLP production and virion release of a residue that does not belong to L domain and may advance our understanding of HPIV3 viral assembly and budding.