AUTHOR=Cheng Wenjie , Chen Qikang , Ren Yilin , Zhang Ye , Lu Liqun , Gui Lang , Xu Dan TITLE=The identification of viral ribonucleotide reductase encoded by ORF23 and ORF141 genes and effect on CyHV-2 replication JOURNAL=Frontiers in Microbiology VOLUME=14 YEAR=2023 URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1154840 DOI=10.3389/fmicb.2023.1154840 ISSN=1664-302X ABSTRACT=Introduction

Ribonucleotide reductase (RR) is essential for the replication of the double-stranded DNA virus CyHV-2 due to its ability to catalyze the conversion of ribonucleotides to deoxyribonucleotides, and is a potential target for the development of antiviral drugs to control CyHV-2 infection.

Methods

Bioinformatic analysis was conducted to identify potential homologues of RR in CyHV-2. The transcription and translation levels of ORF23 and ORF141, which showed high homology to RR, were measured during CyHV-2 replication in GICF. Co-localization experiments and immunoprecipitation were performed to investigate the interaction between ORF23 and ORF141. siRNA interference experiments were conducted to evaluate the effect of silencing ORF23 and ORF141 on CyHV-2 replication. The inhibitory effect of hydroxyurea, a nucleotide reductase inhibitor, on CyHV-2 replication in GICF cells and RR enzymatic activity in vitro was also evaluated.

Results

ORF23 and ORF141 were identified as potential viral ribonucleotide reductase homologues in CyHV-2, and their transcription and translation levels increased with CyHV-2 replication. Co-localization experiments and immunoprecipitation suggested an interaction between the two proteins. Simultaneous silencing of ORF23 and ORF141 effectively inhibited the replication of CyHV-2. Additionally, hydroxyurea inhibited the replication of CyHV-2 in GICF cells and the in vitro enzymatic activity of RR.

Conclusion

These results suggest that the CyHV-2 proteins ORF23 and ORF141 function as viral ribonucleotide reductase and their function makes an effect to CyHV-2 replication. Targeting ribonucleotide reductase could be a crucial strategy for developing new antiviral drugs against CyHV-2 and other herpesviruses.