title: Identification of two functional nuclear localization signals in the capsid protein of duck circovirus.
abstract: The capsid protein (CP) of duck circovirus (DuCV) is the major immunogenic protein and has a high proportion of arginine residues concentrated at the N terminus of the protein, which inhibits efficient mRNA translation in prokaryotic expression systems. In this study, we investigated the subcellular distribution of DuCV CP expressed via recombinant baculoviruses in Sf9 cells and the DNA binding activities of the truncated recombinant DuCV CPs. The results showed that two independent bipartite nuclear localization signals (NLSs) situated at N-terminal 1-17 and 18-36 amino acid residue of the CP. Moreover, two expression level regulatory signals (ELRSs) and two DNA binding signals (DBSs) were also mapped to the N terminus of the protein and overlapped with the two NLSs. The ability of CP to bind DNA, coupled with the karyophilic nature of this protein, strongly suggests that it may be responsible for nuclear targeting of the viral genome.
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Shandong, Taian 271018, China.
authors.forename: Qi-Wang
authors.initials: QW
authors.lastname: Xiang
authors.forename: Jin-Feng
authors.initials: JF
authors.lastname: Zou
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Ya-Ni
authors.initials: YN
authors.lastname: Sun
authors.forename: Ji-Ming
authors.initials: JM
authors.lastname: Gao
authors.forename: Zhi-Jing
authors.initials: ZJ
authors.lastname: Xie
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Yan-Li
authors.initials: YL
authors.lastname: Zhu
authors.forename: Shi-Jin
authors.initials: SJ
authors.lastname: Jiang
mesh_terms: D000818:Animals; D016367:Baculoviridae / Q000235:genetics; D036022:Capsid Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D017925:Circovirus / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism; D004372:Ducks / Q000821:virology; D016679:Genome, Viral; D019913:Nuclear Localization Signals / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D061987:Sf9 Cells; D015398:Signal Transduction; D014779:Virus Replication
chemical_list: D036022:Capsid Proteins; D004268:DNA-Binding Proteins; D019913:Nuclear Localization Signals; D011994:Recombinant Proteins