Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València, Avda. Ingeniero Fausto Elio, 46022 Valencia, Spain.
Centro de Edafología y Biología Aplicada del Segura (CEBAS)-CSIC, Departamento de Biología del Estrés y Patología Vegetal, 30100 Murcia, Spain.
Viruses. 2022 Aug 4;14(8):1718. doi: 10.3390/v14081718.
We have previously reported the presence of mA in the AMV (Alfamovirus, ) genome. Interestingly, two of these putative mA-sites are in hairpin (hp) structures in the 3'UTR of the viral RNA3. One site (AAACU) is in the loop of hpB, within the coat protein binding site 1 (CPB1), while the other (UGACC) is in the lower stem of hpE, a loop previously associated with AMV negative-strand RNA synthesis. In this work, we have performed in vivo experiments to assess the role of these two regions, containing the putative mA-sites in the AMV cycle, by introducing compensatory point mutations to interfere with or abolish the mA-tag of these sites. Our results suggest that the loop of hpB could be involved in viral replication/accumulation. Meanwhile, in the UGACC motif of the hpE, the maintenance of the adenosine residue and the lower stem hpE structure are necessary for in vivo plus-strand accumulation. These results extend our understanding of the requirements for hpE in the AMV infection cycle, indicating that both the residue identity and the base-pairing capacity in this structure are essential for viral accumulation.
我们之前曾报道过 mA 存在于 AMV（Alfamovirus，）基因组中。有趣的是，这些推定的 mA 位点中有两个位于病毒 RNA3 的 3'UTR 中的发夹（hp）结构中。一个位点（AAACU）位于 hpB 的环中，位于衣壳蛋白结合位点 1（CPB1）内，而另一个（UGACC）位于 hpE 的下茎中，该环先前与 AMV 负链 RNA 合成有关。在这项工作中，我们通过引入补偿性点突变来干扰或消除这些位点的 mA 标签，从而在体内进行实验以评估这两个包含推定 mA 位点的区域在 AMV 周期中的作用。我们的结果表明，hpB 的环可能参与病毒复制/积累。同时，在 hpE 的 UGACC 基序中，腺嘌呤残基的维持和 hpE 结构的下茎对于体内正链积累是必需的。这些结果扩展了我们对 hpE 在 AMV 感染周期中的要求的理解，表明该结构中的残基身份和碱基配对能力对于病毒积累都是必不可少的。
