title: Identification of non-essential regions in nucleocapsid protein of porcine reproductive and respiratory syndrome virus for replication in cell culture.
abstract: Nucleocapsid (N) protein of porcine reproductive and respiratory syndrome virus (PRRSV) plays a central role in virus replication. In this study, serial N- and C-terminal truncations of N protein were performed in the context of type 2 PRRSV infectious cDNA clone, and our results revealed that a stretch of inter-genotypic variable N terminal residues aa 5-13 ((5)NGKQQKKK(13)K) and the last four inter-genotypic variable aa residues ((120)SPS(123)A) at the C terminus of N protein were dispensable for type 2 PRRSV infectivity. All the recovered deletion mutant viruses had spontaneous mutations in the N coding region, including substitution, deletion and insertion. We re-engineered the additional internal deletion with or without the original C-terminal deletion back into wild-type APRRS and found that the internal domain spanning the inter-genotypic variable residues 39-42 ((39)KGP(42)G) and conserved residues 48-52 ((48)KNPE(52)K), respectively, were dispensable for type 2 PRRSV viability. These results demonstrated that N protein contains non-essential regions for virus viability in cell culture. Such dispensable regions could be utilized as insertion site for foreign tag expression and the rescued viruses could be the candidates for marker vaccine.
authors: Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 518 Ziyue Road, Shanghai 200241, China.
authors: Feifei
authors: F
authors: Tan
authors: Zuzhang
authors: Z
authors: Wei
authors: Yanhua
authors: Y
authors: Li
authors: Rong
authors: R
authors: Zhang
authors: Jinshan
authors: J
authors: Zhuang
authors: Zhi
authors: Z
authors: Sun
authors: Shishan
authors: S
authors: Yuan
mesh_terms: D018929:Cell Culture Techniques; D004252:DNA Mutational Analysis; D050296:Microbial Viability; D016254:Mutagenesis, Insertional; D019590:Nucleocapsid Proteins / Q000235:genetics* / Q000378:metabolism*; D017354:Point Mutation; D019316:Porcine respiratory and reproductive syndrome virus / Q000235:genetics* / Q000254:growth & development*; D017384:Sequence Deletion; D014779:Virus Replication
chemical_list: D019590:Nucleocapsid Proteins