title: Quantitative interactome reveals that porcine reproductive and respiratory syndrome virus nonstructural protein 2 forms a complex with viral nucleocapsid protein and cellular vimentin.
abstract: Porcine reproductive and respiratory syndrome virus (PRRSV) is an Arterivirus that has heavily impacted the global swine industry. The PRRSV nonstructural protein 2 (nsp2) plays crucial roles in viral replication and host immune regulation, most likely by interacting with viral or cellular proteins that have not yet been identified. In this study, a quantitative interactome approach based on immunoprecipitation and stable isotope labeling with amino acids in cell culture (SILAC) was performed to identify nsp2-interacting proteins in PRRSV-infected cells with an nsp2-specific monoclonal antibody. Nine viral proteins and 62 cellular proteins were identified as potential nsp2-interacting partners. Our data demonstrate that the PRRSV nsp1α, nsp1β, and nucleocapsid proteins all interact directly with nsp2. Nsp2-interacting cellular proteins were classified into different functional groups and an interactome network of nsp2 was generated. Interestingly, cellular vimentin, a known receptor for PRRSV, forms a complex with nsp2 by using viral nucleocapsid protein as an intermediate. Taken together, the nsp2 interactome under the condition of virus infection clarifies a role of nsp2 in PRRSV replication and immune evasion.
  
  
  
  Viral proteins must interact with other virus-encoded proteins and/or host cellular proteins to function, and interactome analysis is an ideal approach for identifying such interacting proteins. In this study, we used the quantitative interactome methodology to identify the viral and cellular proteins that potentially interact with the nonstructural protein 2 (nsp2) of porcine reproductive and respiratory syndrome virus (PRRSV) under virus infection conditions, thus providing a rich source of potential viral and cellular interaction partners for PRRSV nsp2. Based on the interactome data, we further demonstrated that PRRSV nsp2 and nucleocapsid protein together with cellular vimentin, form a complex that may be essential for viral attachment and replication, which partly explains the role of nsp2 in PRRSV replication and immune evasion.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, PR China.
authors.forename: Tao
authors.initials: T
authors.lastname: Song
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, PR China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, PR China.
authors.forename: Liurong
authors.initials: L
authors.lastname: Fang
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, PR China.
authors.forename: Dang
authors.initials: D
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, PR China.
authors.forename: Ruoxi
authors.initials: R
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, PR China.
authors.forename: Songlin
authors.initials: S
authors.lastname: Zeng
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, PR China.
authors.forename: Kang
authors.initials: K
authors.lastname: An
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, PR China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, PR China.
authors.forename: Huanchun
authors.initials: H
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, PR China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, PR China. Electronic address: vet@mail.hzau.edu.cn.
authors.forename: Shaobo
authors.initials: S
authors.lastname: Xiao
mesh_terms: D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D057809:HEK293 Cells; D006801:Humans; D019590:Nucleocapsid Proteins / Q000737:chemistry*; D019316:Porcine respiratory and reproductive syndrome virus / Q000737:chemistry*; D060066:Protein Interaction Maps; D055503:Protein Multimerization; D013552:Swine; D014746:Vimentin / Q000737:chemistry*; D017361:Viral Nonstructural Proteins / Q000737:chemistry*; D014764:Viral Proteins / Q000737:chemistry
chemical_list: D019590:Nucleocapsid Proteins; D014746:Vimentin; D017361:Viral Nonstructural Proteins; D014764:Viral Proteins
keywords: Immunoprecipitation; Interactome; Nonstructural protein 2 (nsp2); Porcine reproductive and respiratory syndrome virus (PRRSV); Stable isotope labeling with amino acids in cell culture (SILAC)