PDF(Pubmed)
Abstract：
Ebola virus (EBOV) is a filamentous negative-sense RNA virus which causes severe hemorrhagic fever. There are limited vaccines or therapeutics for prevention and treatment of EBOV, so it is important to get a detailed understanding of the virus lifecycle to illuminate new drug targets. EBOV encodes for the matrix protein, VP40, which regulates assembly and budding of new virions from the inner leaflet of the host cell plasma membrane (PM). In this work we determine the effects of VP40 mutations altering electrostatics on PM interactions and subsequent budding. VP40 mutations that modify surface electrostatics affect viral assembly and budding by altering VP40 membrane binding capabilities. Mutations that increase VP40 net positive charge by one (e.g., Gly to Arg or Asp to Ala) increase VP40 affinity for phosphatidylserine (PS) and PI(4,5)P2 in the host cell PM. This increased affinity enhances PM association and budding efficiency leading to more effective formation of virus-like particles (VLPs). In contrast, mutations that decrease net positive charge by one (e.g., Gly to Asp) lead to a decrease in assembly and budding because of decreased interactions with the anionic PM. Taken together our results highlight the sensitivity of slight electrostatic changes on the VP40 surface for assembly and budding. Understanding the effects of single amino acid substitutions on viral budding and assembly will be useful for explaining changes in the infectivity and virulence of different EBOV strains, VP40 variants that occur in nature, and for long-term drug discovery endeavors aimed at EBOV assembly and budding.
摘要：
埃博拉病毒（EBOV）是一种丝状阴性RNA病毒，可引起严重的出血热。用于预防和治疗EBOV的疫苗或疗法有限，因此，详细了解病毒生命周期以阐明新的药物靶标非常重要。EBOV编码基质蛋白，VP40,其调节来自宿主细胞质膜(PM)的内小叶的新病毒体的组装和出芽。在这项工作中，我们确定了VP40突变改变静电对PM相互作用和随后的出芽的影响。改变表面静电的VP40突变通过改变VP40膜结合能力影响病毒组装和出芽。将VP40净正电荷增加一个的突变(例如，Gly至Arg或Asp至Ala）增加VP40对宿主细胞PM中磷脂酰丝氨酸（PS）和PI（4,5）P2的亲和力。这种增加的亲和力增强了PM缔合和出芽效率,导致更有效地形成病毒样颗粒(VLP)。相比之下,使净正电荷减少一个的突变(例如，Gly至Asp）由于与阴离子PM的相互作用减少，导致组装和出芽减少。总之，我们的结果突出了VP40表面上轻微的静电变化对组装和出芽的敏感性。了解单个氨基酸取代对病毒出芽和组装的影响将有助于解释不同EBOV毒株的感染性和毒力的变化。在自然界中发生的VP40变体，以及针对EBOV组装和萌芽的长期药物发现努力。
