Molecular characterization of the pseudorabies virus UL2 gene

Abstract

ABSTRACT.A 948-bp sequence of the UL2 gene was amplified from the pseudorabies virus (PRV) Becker strain genome using polymerase chain reaction, and the gene identity was confirmed through further cloning and sequencing. Bioinformatic analysis indicated that the PRV UL2 gene encodes a putative polypeptide with 315-amino acid residues. Its encoding protein, designated UL2, has a conserved uracil-DNA glycosylase (UDG)_F1 domain, which is closely related to the herpesvirus UDG family and is highly conserved among its counterparts encoded by UDG genes. Multiple nucleic acid and amino acid sequence alignments suggested that the product of PRV UL2 has a relatively higher homology with UL2-like proteins of Alphaherpesvirinae than that of other subfamilies of Herpesviridae. In addition, phylogenetic analysis showed that PRV UL2 had a close evolutionary relationship with members of Alphaherpesvirinae, especially members of the genus Varicellovirus of bovine herpesvirus 1 and bovine herpesvirus 5. Antigen prediction indicated the presence of several potential B-cell epitopes in PRV UL2. In addition, secondary structure and 3-dimensional structure prediction revealed that PRV UL2 consisted predominantly of an α-helix. Taken together, these results provide molecular biological insight for the further study of the function and mechanism of UL2 during PRV infection.

The nuclear localization signal-mediated nuclear targeting of herpes simplex virus 1 early protein UL2 is important for efficient viral production

“…Herpesviral UDG is reported to be a multi-functional protein, which is highly conserved and important for the production of viral DNA among HSV-1 UL2, HSV-2 UL2, pseudorabies virus (PRV) UL2, HCMV UL114, varicella-zoster virus ORF59 and human herpesvirus 6 U81. Specifically, UDG is involved in the base cutting repair pathway, which correctly detaches the erroneously inserted uracil from synthetic viral DNA [5,8,33]. Studies have shown that the NLSs of some viral proteins are required for the efficient virus replication.…”

Probing the nuclear import signal and nuclear transport molecular determinants of PRV ICP22

“…After the PCR amplified product was validated as the intended product, it was purified using a PCR gel purification kit (Qiagen) according to the manufacturer’s instructions. The product was then digested with EcoR I and BamH I and inserted into the correspondingly digested green fluorescent protein variant mammalian expression vector pEYFP-N1 (Clontech) encoding EYFP at 16 °C overnight using T4 DNA ligase, to create the recombinant plasmid named pP-ICP22-EYFP, as described previously [ 3 , 26 , 50 – 53 ]. After mini-scale isolation of plasmid DNA using Qiagen plasmid Mini kits (Qiagen), the presence of the appropriate insert in the obtained plasmid was confirmed by PCR, restriction analysis and sequencing.…”