The host genome targeting potyviral proteins is sparsely reported. Viral genome-linked protein (VPg) is a multifaceted protein known for its interactions with a suite of host proteins, guides essential viral life cycle processes such as genome replication, translation, genome packing, and antiviral defence. Besides, VPg also plays a crucial role in assisting the transport of nuclear inclusion a protease (NIa protease) into the host nucleus. Apart from that, the role of VPg in the nucleus of the cognate host is not clear. Although NIa protease has been reported for DNase activity, the molecular mechanisms underlying host genome accessibility are not yet understood completely. Here, we employed yeast two hybrid assays to test the cardamom histones H3 and H4 interaction with the VPg and NIa protease of macluravirus cardamom mosaic virus (CdMV). Although CdMV NIa protease has the putative histone-binding ER motif of MYST histone acetyltransferase, it did not interact with host histones H3 and H4. Surprisingly, CdMV VPg displayed strong interaction with histone proteins H3 and H4. Leucine prototrophy and β-galactosidase assays were performed which validated VPg interaction with histones. To the best of our knowledge, this study is the first report for the multipartnered potyvirid protein VPg interaction with host histones H3 and H4.

针对多病毒蛋白的宿主基因组的报道很少。病毒基因组相关蛋白 (VPg) 是一种多方面的蛋白质，以其与一系列宿主蛋白的相互作用而闻名，指导基本的病毒生命周期过程，如基因组复制、翻译、基因组包装和抗病毒防御。此外，VPg 在协助核内含蛋白酶 (NIa protease) 转运到宿主细胞核中也起着至关重要的作用。除此之外，VPg 在同源宿主细胞核中的作用尚不清楚。尽管已经报道了 NIa 蛋白酶的 DNase 活性，但尚未完全了解宿主基因组可及性的分子机制。在这里，我们使用酵母两种杂交试验来测试豆蔻组蛋白 H3 和 H4 与黄斑病毒的 VPg 和 NIa 蛋白酶的相互作用豆蔻花叶病毒（CdMV）。尽管 CdMV NIa 蛋白酶具有推定的 MYST 组蛋白乙酰转移酶的组蛋白结合 ER 基序，但它不与宿主组蛋白 H3 和 H4 相互作用。令人惊讶的是，CdMV VPg 显示出与组蛋白 H3 和 H4 的强相互作用。进行了亮氨酸原养和 β-半乳糖苷酶测定，验证了 VPg 与组蛋白的相互作用。据我们所知，这项研究是多伙伴病毒蛋白 VPg 与宿主组蛋白 H3 和 H4 相互作用的第一份报告。