Porcine deltacoronavirus (PDCoV) has been recently identified as an emerging enteropathogenic coronavirus that mainly infects newborn piglets and causes enteritis, diarrhea and high mortality. Although coronavirus N proteins have multifarious activities, the subcellular localization of the PDCoV N protein is still unknown. Here, we produced mouse monoclonal antibodies against the PDCoV N protein. Experiments using anti-haemagglutinin antibodies and these monoclonal antibodies revealed that the PDCoV N protein is shuttled into the nucleolus in both ectopic PDCoV N-expressing cells and PDCoV-infected cells. The results of deletion mutagenesis experiments demonstrated that the predicted nucleolar localization signal at amino acids 295–318 is critical for nucleolar localization. Cumulatively, our study yielded a monoclonal antibody against the PDCoV N protein and revealed a mechanism by which the PDCoV N protein translocated into the nucleolus. The tolls and findings from this work will facilitate further investigations on the functions of the PDCoV N protein.

猪三角冠状病毒（PDCoV）最近被确定为一种新兴的肠道致病性冠状病毒，主要感染新生仔猪并引起肠炎、腹泻和高死亡率。尽管冠状病毒 N 蛋白具有多种活性，但 PDCoV N 蛋白的亚细胞定位仍然未知。在这里，我们生产了针对 PDCoV N 蛋白的小鼠单克隆抗体。使用抗血凝素抗体和这些单克隆抗体的实验表明，PDCoV N 蛋白在异位 PDCoV N 表达细胞和 PDCoV 感染细胞中都穿梭到核仁中。缺失诱变实验的结果表明，预测的 295-318 位氨基酸的核仁定位信号对核仁定位至关重要。累积起来，我们的研究产生了一种针对 PDCoV N 蛋白的单克隆抗体，并揭示了 PDCoV N 蛋白易位进入核仁的机制。这项工作的收费和发现将有助于进一步研究 PDCoV N 蛋白的功能。