Research Center in Infectious Diseases, CHU de Québec- Laval University, Quebec City, QC, Canada.
Department of Biochemistry, Microbiology and Bioinformatics, PROTEO, And Institute of Integrative and Systems Biology, Laval University, Quebec City, QC, Canada.
Antiviral Res. 2021 Apr;188:105046. doi: 10.1016/j.antiviral.2021.105046. Epub 2021 Feb 12.
This study aimed at understanding the impact of different substitutions at codon 715 localized in the region II of the palm domain of herpes simplex virus 1 (HSV-1) and human cytomegalovirus (HCMV) DNA polymerases (pol). Here, we report a new theoretical mutation V715S that confers resistance of HSV-1 to foscarnet/acyclovir (5.6- and 9.2-fold increases EC values compared to wild type, respectively) and of HCMV to foscarnet/ganciclovir (2.8- and 2.9-fold increases in EC values compared to wild type, respectively). To further analyze the importance of this amino acid, we investigated the impact of the already known mutations V715M and V715G on the replicative capacities and drug susceptibilities of both viruses as well as on the activity and drug inhibition of the DNA pol. The V715G recombinant HSV-1 mutant was resistant to foscarnet and acyclovir (3.4- and 4.6-fold EC increase, respectively) whereas the V715M mutant was susceptible to foscarnet and resistant to acyclovir (3.4-fold EC increase). The V715G recombinant HCMV mutant did not grow and the V715M mutant was resistant to foscarnet (3.7-fold EC increase) and susceptible to ganciclovir. Finally, we showed by three-dimensional modeling that the differential impact of these mutations on the viral replicative capacity and drug resistance profile was related to different hydrophobic local environments for V715 in the DNA pol of the two viruses. Furthermore, we hypothesize that the DNA pol of HSV-1 is more tolerant to changes at this residue compared to that of HCMV because of a more hydrophobic environment stabilizing the region.
本研究旨在探讨位于单纯疱疹病毒 1 (HSV-1) 和人巨细胞病毒 (HCMV) DNA 聚合酶 (pol) palm 结构域区域 II 中密码子 715 处不同取代对病毒的影响。在这里，我们报告了一种新的理论突变 V715S，该突变使 HSV-1 对磷甲酸钠/阿昔洛韦 (与野生型相比，EC 值分别增加了 5.6 倍和 9.2 倍) 产生耐药性，使 HCMV 对磷甲酸钠/更昔洛韦 (与野生型相比，EC 值分别增加了 2.8 倍和 2.9 倍) 产生耐药性。为了进一步分析该氨基酸的重要性，我们研究了已发现的突变 V715M 和 V715G 对两种病毒复制能力和药物敏感性的影响，以及对 DNA pol 活性和药物抑制的影响。V715G 重组 HSV-1 突变体对磷甲酸钠和阿昔洛韦具有耐药性 (EC 值分别增加了 3.4 倍和 4.6 倍)，而 V715M 突变体对磷甲酸钠敏感，对阿昔洛韦耐药 (EC 值增加了 3.4 倍)。V715G 重组 HCMV 突变体不能生长，V715M 突变体对磷甲酸钠耐药，对更昔洛韦敏感。最后，我们通过三维建模表明，这些突变对病毒复制能力和耐药谱的不同影响与两种病毒的 DNA pol 中 V715 不同的疏水性局部环境有关。此外，我们假设 HSV-1 的 DNA pol 对该残基的变化比 HCMV 的更耐受，因为更疏水的环境稳定了该区域。
