Tumor Susceptibility Gene 101 (TSG101) Contributes to Virion Formation of Porcine Reproductive and Respiratory Syndrome Virus via Interaction with the Nucleocapsid (N) Protein along with the Early Secretory Pathway

Abstract

Porcine reproductive and respiratory syndrome virus (PRRSV) has caused huge economic losses to global swine industry. As an intracellular obligate pathogen, PRRSV exploits host cellular machinery to establish infection. The endocytic sorting complex required for transport (ESCRT) system has been shown to participate in different life cycle stages of multiple viruses. In the current study, a systematic small interference RNA (siRNA) screening assay identified that certain ESCRT components contributed to PRRSV infection. Among them, tumor susceptibility gene 101 (TSG101) was demonstrated to be important for PRRSV infection by knockdown and overexpression assays. TSG101 was further revealed to be involved in virion formation rather than viral attachment, internalization, RNA replication and nucleocapsid (N) protein translation within the first round of PRRSV life cycle. In detail, TSG101 was determined to specially interact with PRRSV N protein and take effect on its subcellular localization along with the early secretory pathway. Taken together, these results provide evidence that TSG101 is a pro-viral cellular factor for PRRSV assembly, which will be a promising target to interfere with the viral infection. IMPORTANCE PRRSV infection results in a serious swine disease affecting pig farming in the world. However, efficient prevention and control of PRRSV is hindered by its complicated infection process. Up to now, our understanding of PRRSV assembly during infection is especially limited. Here, we identified that TSG101, an ESCRT-I subunit, facilitated virion formation of PRRSV via interaction with the viral N protein along with the early secretory pathway. Our work actually expands the knowledge of PRRSV infection and provides a novel therapeutic target for prevention and control of the virus.

ALIX and TSG101 are essential for cellular entry and replication of two porcine alphacoronaviruses

“…However, Japanese encephalitis virus (JEV) and dengue virus (DENV) rely on ESCRT to form viral particles rather than replication organelles [ 14 ]. Similar results have been reported for hepatitis C virus (HCV) [ 45 ] and porcine reproductive and respiratory syndrome virus (PRRSV) [ 46 ]. This indicates that the regulation of virus replication by ALIX and TSG101 is not only related to DMV formation but may also be associated with the formation of mature viral particles.…”

Hepatitis B virus hijacks TSG101 to facilitate egress via multiple vesicle bodies

“…In addition, TSG101 can facilitate influenza A virus trafficking, but this is effectively restricted by the interferon-stimulated gene 15 [ 31 ]. A recent paper showed that TSG101 contributed to virion formation of porcine reproductive and respiratory syndrome virus via interaction with the nucleocapsid protein [ 32 ]. Although a previous study demonstrates that TSG101 does not affect HBV production in plasmid transfection system [ 33 ], different observations were obtained in HBV replicating and infection cells.…”

Porcine reproductive and respiratory syndrome virus triggers Golgi apparatus fragmentation-mediated autophagy to facilitate viral self-replication

“…In the case that overexpression of GRASP65 inhibited PRRSV/Nsp2-induced GA fragmentation ( Fig. 5 ), we assessed PRRSV RNA replication by detecting the intermediate of PRRSV RNA synthesis, double-stranded RNA (dsRNA), in the GRASP65-myc-overexpressed-MARC-145 cells via indirect immunofluorescence assay (IFA) and flow cytometry (FCM) at 10 hpi during the first viral life cycle ( 48 ). The results showed significant reductions in dsRNA abundance as indicated by ~75% reduction detected by IFA ( Fig.…”