Department of Virology, School of Public Health, Cheeloo College of Medicine, Shandong University, Ji'nan, Shandong, China.
Department of Health Management and Services, Cangzhou Medical College, Cangzhou, Hebei, China.
Biosci Trends. 2021 Mar 15;15(1):16-23. doi: 10.5582/bst.2020.03317. Epub 2021 Jan 27.
Newcastle disease (ND), caused by the Newcastle disease virus (NDV), is transmitted by poultry with severe infectivity and a high fatality rate. The fusion (F) protein on the NDV envelope facilitates the merger of the viral and host cell membranes with the help of the homologous hemagglutinin-neuraminidase protein (HN). The transmembrane (TM) domains of viral fusion proteins are typically required for fusion, but the key amino acids in NDV F TM domains have not been identified. Site-directed mutagenesis was utilized to change the conserved amino acids at 500, 501, 502, 505, 510, 513, 516, 519, and 520 to alanine. It was found that mutants L519 and V520 had an interrupted protein expression, decreased to below 10%, and mutants A500, I505, V513, and V516 had a hypoactive impact on fusion activity, decreased to 85.38%, 67.05%, 55.38% and 51.13% of wt F, respectively. The results indicated that the TM domain plays a vital part in the fusion activity of the NDV F protein.
新城疫（ND）由新城疫病毒（NDV）引起，通过具有严重传染性和高死亡率的家禽传播。NDV 包膜上的融合（F）蛋白在同源血凝素神经氨酸酶蛋白（HN）的帮助下促进病毒和宿主细胞膜的融合。病毒融合蛋白的跨膜（TM）结构域通常是融合所必需的，但 NDV F TM 结构域中的关键氨基酸尚未确定。通过定点突变将 500、501、502、505、510、513、516、519 和 520 位的保守氨基酸突变为丙氨酸。结果发现，突变体 L519 和 V520 的蛋白表达中断，降至 10%以下，而突变体 A500、I505、V513 和 V516 的融合活性呈低活性，分别降至 wt F 的 85.38%、67.05%、55.38%和 51.13%。结果表明，TM 结构域在 NDV F 蛋白的融合活性中起着至关重要的作用。
