Nayak B Nagaraj, Rajagopal Kalaimagal, Shunmugasundaram Revathi, Rao Pachineella Lakshmana, Vaidyanathan Saraswathy, Subbiah Madhuri
National Institute of Animal Biotechnology, Hyderabad, Telangana India.
Regional Centre for Biotechnology, New Delhi, India.
Virusdisease. 2023 Jun;34(2):236-247. doi: 10.1007/s13337-023-00813-2. Epub 2023 May 2.
Viruses adopt strategies to efficiently utilize their compact genome. Members of the family , exhibit a cotranscriptional RNA editing mechanism wherein polymerase stuttering generates accessory proteins from Phosphoprotein () gene. Newcastle disease virus (NDV), an avian paramyxovirus, expresses two accessory proteins, V and W, by RNA editing. While P and V proteins are well studied, very little is known about W protein. Recent studies confirmed W protein expression in NDV and the unique subcellular localization of W proteins of virulent and avirulent NDV. We characterized the W protein of NDV strain Komarov, a moderately virulent vaccine strain. W mRNA expression ranged between 7 and 9% of total gene transcripts similar to virulent NDV. However, W protein expression, detectable by 6 h, peaked at 24 h and dropped by 48 h post infection in DF1 cells indicating a kinetically regulated expression by the virus. The W protein localized in the nucleus and by mutations, a strong nuclear localization signal was identified in the C-terminal region of W protein. The viral growth kinetics study suggested neither supplementation of W protein nor subcellular localization pattern of the supplemented W protein influenced viral replication in vitro similar to that noticed in avirulent NDV. A cytoplasmic mutant of W protein localized in cytoplasm unlike specific mitochondrial colocalization as recorded in velogenic NDV strain SG10 indicating a possible role of W protein in determining the viral pathogenicity. This study describes for the first time, the distinct features of W protein of moderately virulent NDV.
The online version contains supplementary material available at 10.1007/s13337-023-00813-2.
病毒采用策略来有效利用其紧凑的基因组。该家族的成员表现出一种共转录RNA编辑机制，其中聚合酶滑动从磷蛋白（P）基因产生辅助蛋白。新城疫病毒（NDV）是一种禽副粘病毒，通过RNA编辑表达两种辅助蛋白V和W。虽然对P蛋白和V蛋白已有充分研究，但对W蛋白却知之甚少。最近的研究证实了NDV中W蛋白的表达以及强毒株和无毒株NDV的W蛋白独特的亚细胞定位。我们对中等毒力疫苗株Komarov的NDV的W蛋白进行了表征。W mRNA表达量占总P基因转录本的7%至9%，与强毒株NDV相似。然而，W蛋白表达在感染后6小时可检测到，在DF1细胞中于24小时达到峰值，并在48小时下降，表明该病毒对其表达进行了动力学调控。W蛋白定位于细胞核，通过突变，在W蛋白的C末端区域鉴定出一个强核定位信号。病毒生长动力学研究表明，补充W蛋白或补充的W蛋白的亚细胞定位模式均未影响体外病毒复制，这与无毒株NDV的情况相似。W蛋白的细胞质突变体定位于细胞质，与速发型NDV毒株SG10中记录的特异性线粒体共定位不同，这表明W蛋白在决定病毒致病性方面可能发挥作用。本研究首次描述了中等毒力NDV的W蛋白的独特特征。
在线版本包含可在10.1007/s13337-023-00813-2获取的补充材料。
