PDF(Pubmed)
Abstract：
Influenza A virus (IAV) is a respiratory pathogen that causes seasonal epidemics with significant mortality. One of the most abundant proteins in IAV particles is the matrix protein 1 (M1), which is essential for the virus structural stability. M1 organizes virion assembly and budding at the plasma membrane (PM), where it interacts with other viral components. The recruitment of M1 to the PM as well as its interaction with the other viral envelope proteins (hemagglutinin [HA], neuraminidase, matrix protein 2 [M2]) is controversially discussed in previous studies. Therefore, we used fluorescence fluctuation microscopy techniques (i.e., scanning fluorescence cross-correlation spectroscopy and number and brightness) to quantify the oligomeric state of M1 and its interactions with other viral proteins in co-transfected as well as infected cells. Our results indicate that M1 is recruited to the PM by M2, as a consequence of the strong interaction between the two proteins. In contrast, only a weak interaction between M1 and HA was observed. M1-HA interaction occurred only in the event that M1 was already bound to the PM. We therefore conclude that M2 initiates the assembly of IAV by recruiting M1 to the PM, possibly allowing its further interaction with other viral proteins.
摘要：
甲型流感病毒(IAV)是引起季节性流行并具有显著死亡率的呼吸道病原体。IAV颗粒中最丰富的蛋白质之一是基质蛋白1（M1），这对病毒的结构稳定性至关重要。M1在质膜（PM）组织病毒体组装和出芽，它与其他病毒成分相互作用。M1对PM的募集以及其与其他病毒包膜蛋白（血凝素[HA]，神经氨酸酶，基质蛋白2[M2]）在先前的研究中存在争议。因此,我们使用了荧光波动显微镜技术(即，扫描荧光互相关光谱以及数量和亮度），以量化M1的寡聚状态及其与共转染和感染细胞中其他病毒蛋白的相互作用。我们的结果表明，由于两种蛋白质之间的强烈相互作用，M2将M1募集到PM中。相比之下,仅观察到M1和HA之间的弱相互作用。M1-HA相互作用仅在M1已经与PM结合的情况下发生。因此，我们得出结论，M2通过将M1招募到PM来启动IAV的组装，可能允许其与其他病毒蛋白的进一步相互作用。
