Duck plague virus US3 protein kinase phosphorylates UL47 and regulates the subcellular localization of UL47

Abstract

Duck plague virus (DPV) belongs to the alphaherpesvirinae and causes high morbidity and mortality in waterfowl. UL47 is a large abundant structural protein in DPV, which means that UL47 protein plays an important role in virus replication. US3 protein, as a viral protein kinase in alphaherpesviruses, has been reported to be critical for DPV virion assembly. In this study, we over-expressed UL47 and US3 proteins and found that DPV UL47 protein was a phosphorylated substrate of US3 protein, which interacted and co-localized with US3 protein in the cytoplasm. US3-regulated phosphorylation of UL47 was important for the cytoplasmic localization of UL47 because non-phosphorylated UL47 was localized in the nucleus. The six sites of UL47 at Thr29, Ser30, Ser42, Thr47, Ser161, and Thr775 were identified as the phosphorylation targets of US3 protein. In vivo, UL47 phosphorylation was also detected but not in ΔUS3-infected cells. US3 protein promoted the cytoplasmic localization of UL47 at the late stage of infection, and the lack of US3 protein caused a delay in UL47 translocation to the cytoplasm. These results enhance our understanding of the functions of US3 during DPV infection and provide some references for DPV assembly.

Effects of US3 protein kinase activity on localization of UL31/UL34 protein and nucleocapsids egress of duck plague virus

“…However, US3K213A mutant had a slightly higher growth curve than that of △US3 ( Figure 3 ), indicating that there might be other domains, such as autophosphorylation areas, in pUS3 that also play a role in DPV replication. In addition, a decrease of pUL47 expression was observed in △US3 or US3K213A-infected cells ( Figure 1B ), which was also found in our recently published report where it interpreted that DPV pUS3 phosphorylated pUL47 resulting in a possibility of increased stability of pUL47 in the cytoplasm ( Deng et al, 2022 ).…”

Mechanism of herpesvirus UL24 protein regulating viral immune escape and virulence

“…The expression of proteins is affected by many factors such as interactions between viral proteins form a complex network and can affect the expression or function of other viral proteins. The proteins can combine into complexes to serve the entire life cycle of the virus ( Reynolds et al, 2002 ; Ryckman and Roller, 2004 ; Liu et al, 2014 ; Takeshima et al, 2019 ; Deng et al, 2022 ). ICP27 is a conserved immediate early protein of herpesviruses that is involved in gene regulation at different stages of the virus.…”

Duck plague virus Us3 regulates the expression of pUL48

“…For example, it can catalyze the phosphorylation of VHS to regulate the degradation of host mRNAs and the shutdown of host protein synthesis ( Tanaka et al, 2005 ; Asai et al, 2007 ; Pennisi et al, 2020 ). Phosphorylation of pUL47 regulates its nuclear localization in infected cells and promotes viral entry into the cytoplasm ( Kato et al, 2011 ; Zhang et al, 2016 ; Deng et al, 2022 ). Phosphorylation of pUL49 regulates its assembly in viral particles ( Ren et al, 2001 , Geiss et al, 2001 , Potel and Elliott, 2005 ).…”