The Ebola virus matrix protein VP40 is responsible for the formation of the viral matrix by localizing at the inner leaflet of the human plasma membrane (PM). Various lipid types, including PI(4,5)P (i.e. PIP) and phosphatidylserine (PS), play active roles in this process. Specifically, the negatively charged headgroups of both PIP and PS interact with the basic residues of VP40 and stabilize it at the membrane surface, allowing for eventual egress. Phosphatidic acid (PA), resulting from the enzyme phospholipase D (PLD), is also known to play an active role in viral development. In this work, we performed a biophysical and computational analysis to investigate the effects of the presence of PA on the membrane localization and association of VP40. We used coarse-grained molecular dynamics simulations to quantify VP40 hexamer interactions with the inner leaflet of the PM. Analysis of the local distribution of lipids shows enhanced lipid clustering when PA is abundant in the membrane. We observed that PA lipids have a similar role to that of PS lipids in VP40 association due to the geometry and charge. Complementary experiments performed in cell culture demonstrate competition between VP40 and a canonical PA-binding protein for the PM. Also, inhibition of PA synthesis reduced the detectable budding of virus-like particles. These computational and experimental results provide new insights into the early stages of Ebola virus budding and the role that PA lipids have on the VP40-PM association.

中文翻译：

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磷脂酸脂对埃博拉病毒基质蛋白VP40质膜结合的作用

埃博拉病毒基质蛋白 VP40 通过定位于人质膜 (PM) 的内叶来负责病毒基质的形成。各种脂质类型，包括 PI(4,5)P（即 PIP）和磷脂酰丝氨酸（PS），在此过程中发挥着积极作用。具体来说，PIP 和 PS 的带负电荷的头基与 VP40 的碱性残基相互作用，并将其稳定在膜表面，从而最终流出。由磷脂酶 D (PLD) 产生的磷脂酸 (PA) 也被认为在病毒发育中发挥着积极作用。在这项工作中，我们进行了生物物理和计算分析，以研究 PA 的存在对 VP40 膜定位和关联的影响。我们使用粗粒度分子动力学模拟来量化 VP40 六聚体与 PM 内叶的相互作用。对脂质局部分布的分析表明，当膜中 PA 丰富时，脂质聚集增强。我们观察到，由于几何形状和电荷，PA 脂质在 VP40 缔合中具有与 PS 脂质相似的作用。在细胞培养物中进行的补充实验证明了 VP40 和典型的 PA 结合蛋白之间对 PM 的竞争。此外，抑制 PA 合成会减少可检测到的病毒样颗粒的出芽。这些计算和实验结果为埃博拉病毒出芽的早期阶段以及 PA 脂质在 VP40-PM 关联中的作用提供了新的见解。