Univ. Limoges, INSERM, CHU Limoges, RESINFIT, U1092, F-87000, Limoges, France.
Univ. Limoges, INSERM, CHU Limoges, RESINFIT, U1092, F-87000, Limoges, France; CHU Limoges, Laboratoire de Bactériologie-Virologie-Hygiène, National Reference Center for Herpesviruses (NRCHV), F-87000, Limoges, France.
Antiviral Res. 2023 Sep;217:105673. doi: 10.1016/j.antiviral.2023.105673. Epub 2023 Jul 20.
Human cytomegalovirus (HCMV) can cause serious diseases in immunocompromised patients. Use of current antivirals is limited by their adverse effects and emergence of drug resistance mutations. Thus, new drugs are an urgent need. The terminase complex (pUL56-pUL89-pUL51) represents a target of choice for new antivirals development. pUL51 was shown to be crucial for the cleavage of concatemeric HCMV DNA and viral replication. Its C-terminal part plays a critical role for the terminase complex assembly. However, no interaction domain is clearly identified. Sequence comparison of herpesvirus homologs and protein modelling were performed on pUL51. Importance of a putative interaction domain is validated by the generation of recombinant viruses with specific alanine substitutions of amino acids implicated in the domain. We identified a Leucine-Zipper (LZ) domain involving the leucine residues L126-X6-L133-X6-L140-X6-L147 in C-terminal part of pUL51. These leucines are crucial for viral replication, suggesting the significance for pUL51 structure and function. A mimetic-peptide approach has been used and tested in antiviral assays to validate the interaction domain as a new therapeutic target. Cytotoxicity was evaluated by LDH release measurement. The peptide TAT-HK29, homologous to the pUL51-LZ domain, inhibits HCMV replication by 27% ± 9% at 1.25 μM concentration without cytotoxicity. Our results highlight the importance of a leucine zipper domain in the C-terminal part of pUL51 involving leucines L126, L133, L140 and L147. We also confirm the potential of mimetic peptides to inhibit HCMV replication and the importance to target interaction domains to develop antiviral agents.
人巨细胞病毒（HCMV）可导致免疫功能低下的患者发生严重疾病。目前抗病毒药物的应用受到其不良反应和耐药突变的限制。因此，急需新的药物。末端酶复合物（pUL56-pUL89-pUL51）是开发新型抗病毒药物的首选靶标。已证实 pUL51 对于连接的 HCMV DNA 的切割和病毒复制至关重要。其 C 末端对于末端酶复合物的组装起着关键作用。但是，没有明确确定相互作用域。对 pUL51 进行疱疹病毒同源物的序列比较和蛋白质建模。通过对涉及该结构域的氨基酸进行特定的丙氨酸取代，生成重组病毒，验证了假定相互作用域的重要性。我们确定了一个亮氨酸拉链（LZ）结构域，该结构域涉及 pUL51 C 末端的亮氨酸残基 L126-X6-L133-X6-L140-X6-L147。这些亮氨酸对病毒复制至关重要，这表明其对 pUL51 结构和功能的重要性。已经使用并在抗病毒测定中测试了模拟肽方法，以验证作为新的治疗靶标的相互作用域。通过测定 LDH 释放来评估细胞毒性。与 pUL51-LZ 结构域同源的 TAT-HK29 肽在 1.25 μM 浓度下对 HCMV 复制的抑制率为 27%±9%，而无细胞毒性。我们的研究结果强调了 pUL51 C 末端的亮氨酸拉链结构域中亮氨酸 L126、L133、L140 和 L147 的重要性。我们还证实了模拟肽抑制 HCMV 复制的潜力，以及靶向相互作用域开发抗病毒药物的重要性。
