Identification and characterization of the duck enteritis virus (DEV) US2 gene

Abstract

ABSTRACT. The US2 protein has been reported to contribute to duck enteritis virus (DEV) infection; however, its kinetics and localization during infection, and whether it is a component of virion, have not been previously reported. To elucidate the function of DEV US2, US2 was amplified by polymerase chain reaction (PCR) and inserted into pET-32a(+); this was expressed, the recombinant US2 protein was purified, and a polyclonal antibody generated. In addition, the kinetics and localization of the US2 gene and protein were determined by quantitative real-time fluorescent PCR, ganciclovir (GCV), and cycloheximide (CHX) treatment, westernblot, and indirect immunofluorescence assay. The packaging of US2 into DEV virions was revealed by a protease protection assay. US2 was found to be transcribed 24 h post-infection (pi) and peaked at 72 h pi; the US2 protein was detected 48 h pi, except in the presence of GCV or CHX. US2 was packed into virions and also localized to the plasma membrane and 13779-13790 (2015) cytoplasm in infected cells. The results showed that the DEV US2 is a late gene, and that its encoding protein could be a tegument component localized mainly in the cytoplasm. This study provides useful data for the further analysis of DEV US2, including an explanation for the genetic conservation among alphaherpesviruses.

Duck virus enteritis (duck plague) – a comprehensive update

“…Partial or complete genomic sequences of DEVs are rapidly accumulating and its analyses demonstrated that, although similar to other herpes viruses, the DEV genome also varies Wang et al 2011;Wu et al 2012a;Wu et al 2012b;Yang et al 2013). The Chinese DEV is a wild type virulent strain of DEV (Gao et al 2015). The genome of the DEV is approximately 158 kb that contains 78 open reading frames (ORFs) predicted to encode potential functional proteins.…”

“…The expressed US2 protein is observed in infected cells through indirect immunofluorescent assay by using fluorescein isothiocyanate (FITC) and purified for assessing its role (Zhao et al 2008;Xiang et al 2010). The DEV gene responsible for US2 protein production also helps in exploring studies of genetic conservation of alpha-herpesviruses besides augmenting the DEV infection because other than in DEV, the US2 protein is also present in other alpha-herpes viruses, including herpes simplex virus-2, bovine herpesvirus-1, equine herpesvirus-1, canine herpesvirus, PRV and Marek's disease virus (Cantello et al 1991;Haanes & Tomlinson 1998;Jiang et al 1998;Belknap et al 1999;Meindl & Osterrieder 1999;Ben-Arieh et al 2001;Clase et al 2003;Gao et al 2015).…”

Duck enteritis virus UL21 is a late gene encoding a protein that interacts with pUL16

“…IE genes are expressed in the presence of CHX although the transcription of E and L genes is suppressed [31]. We also treated DEV-infected cells with GCV and examined UL54 (an IE gene) [32], US2 (an L gene) [33], UL13 (an E gene) [34], and β-actin as controls. We found that UL21 gene expression was inhibited in the groups treated with GCV and CHX.…”

Duck enteritis virus UL21 is a late gene and encodes a protein that interacts with pUL16

“…IE genes are expressed in the presence of CHX, though transcription of E and L genes is suppressed (36). We also treated DEV-infected cells with GCV, a DNA polymerase inhibitor, and we examined UL54 (an IE gene) (37), US2 (an L gene) (38), UL13 (an E gene) (39), and β-actin as controls. We found that UL21 gene expression was inhibited in the groups treated with GCV and CHX.…”