title: The ubiquitin-proteasome system is required for the early stages of porcine circovirus type 2 replication.
abstract: Porcine circovirus type 2 (PCV2) is the primary causative agent of porcine circovirus-associated diseases (PCVAD). It has been shown that the ubiquitin-proteasome system (UPS) is correlated with viral infection, but its role in PCV2 replication remains unknown. In the present study, we explored the interplay between PCV2 replication and the UPS in PK15 cells and found that treatment with a proteasome inhibitor (MG132 and lactacystin) significantly decreased the PCV2 titer at the early infection stage. We further revealed that inhibition of the UPS did not affect virus entry but decreased viral protein expression and RNA transcription potentially in a cell cycle-dependent manner. PCV2 infection has little effect on the chymotrypsin-like activity, and the gene-silencing of ubiquitin reduced the PCV2 titer, which indicates that the effective replication of PCV2 may be related to protein ubiquitination. Taken together, our data suggested that PCV2 replication requires the UPS machinery, which may represent a potential antiviral target against PCV2.
authors.affiliation: Division of Animal Infectious Disease, State Key Laboratory of Agricultural Microbiology, HuaZhong Agricultural University, Wuhan, Hubei 430070, PR China. Electronic address: selice_1234@163.com.
authors.forename: Shuang
authors.initials: S
authors.lastname: Cheng
authors.affiliation: Division of Animal Infectious Disease, State Key Laboratory of Agricultural Microbiology, HuaZhong Agricultural University, Wuhan, Hubei 430070, PR China. Electronic address: yanwd2007@163.com.
authors.forename: Weidong
authors.initials: W
authors.lastname: Yan
authors.affiliation: Division of Animal Infectious Disease, State Key Laboratory of Agricultural Microbiology, HuaZhong Agricultural University, Wuhan, Hubei 430070, PR China. Electronic address: guweifirstg@163.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Gu
authors.affiliation: Division of Animal Infectious Disease, State Key Laboratory of Agricultural Microbiology, HuaZhong Agricultural University, Wuhan, Hubei 430070, PR China. Electronic address: heqigai@yahoo.com.
authors.forename: Qigai
authors.initials: Q
authors.lastname: He
mesh_terms: D000818:Animals; D002460:Cell Line; D017925:Circovirus / Q000502:physiology*; D054884:Host-Pathogen Interactions; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D013552:Swine; D025801:Ubiquitin / Q000378:metabolism*; D019562:Viral Load; D014779:Virus Replication
chemical_list: D025801:Ubiquitin; D046988:Proteasome Endopeptidase Complex
keywords: Lactacystin; MG132; PCV2; PK15 cells; UPS; Viral replication