Xu Liang, Hou Yuwen, Liu Shizhe, Dai Yixin, Ou Jiajun, Ye Shaotang, Wang Zhen, Lu Gang, Li Shoujun
College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
Guangdong Technological Engineering Research Center for Pet, Guangzhou, China.
Front Vet Sci. 2025 Jul 23;12:1641963. doi: 10.3389/fvets.2025.1641963. eCollection 2025.
Tetherin is an interferon-induced-expressing transmembrane protein that utilizes a unique topology to restrict the release of enveloped viruses from the surface of the cell membrane. N-linked glycosylation plays an important role in protein post-translational modifications. To investigate the role of glycosylation in the antiviral activity of canine tetherin, its potential glycosylation sites were predicted and mutated, and the effects of glycosylation site mutations or treatment with a glycosylation inhibitor on the ability of canine tetherin to restrict H3N2 canine influenza virus (CIV) replication were examined. Mutations in the glycosylation sites of canine tetherin (N72A, N99A, and N72,99A) lead to changes in its intracellular distribution and weakened or even lost antiviral activity against H3N2 CIV. Similarly, the subcellular localization of tetherin after tunicamycin treatment was altered, and its antiviral activity was weakened. Colocalization analysis revealed that the colocalization of canine tetherin and H3N2 CIV protein was weakened under the condition of impaired glycosylation. These results indicate that canine tetherin maintains its localization in the cell membrane through glycosylation and exerts its antiviral activity. This study provides new insights into the antiviral mechanisms of host restriction factors and offers a theoretical basis for developing small-molecule anti-influenza strategies targeting glycosylation modifications.
束缚素是一种干扰素诱导表达的跨膜蛋白，它利用独特的拓扑结构来限制包膜病毒从细胞膜表面释放。N-连接糖基化在蛋白质翻译后修饰中起重要作用。为了研究糖基化在犬束缚素抗病毒活性中的作用，预测并突变了其潜在的糖基化位点，并检测了糖基化位点突变或用糖基化抑制剂处理对犬束缚素限制H3N2犬流感病毒（CIV）复制能力的影响。犬束缚素糖基化位点的突变（N72A、N99A和N72,99A）导致其细胞内分布发生变化，并且对H3N2 CIV的抗病毒活性减弱甚至丧失。同样，衣霉素处理后束缚素的亚细胞定位发生改变，其抗病毒活性减弱。共定位分析表明，在糖基化受损的情况下，犬束缚素与H3N2 CIV蛋白的共定位减弱。这些结果表明，犬束缚素通过糖基化维持其在细胞膜中的定位并发挥其抗病毒活性。本研究为宿主限制因子的抗病毒机制提供了新的见解，并为开发针对糖基化修饰的小分子抗流感策略提供了理论基础。
