The N-terminus of porcine circovirus type 2 replication protein is required for nuclear localization and ori binding activities.
Porcine circovirus type 2 possesses a circular, single-stranded DNA genome that requires the replication protein (Rep) for virus replication. To characterize the DNA binding potential and the significant region that confers the nuclear localization of the Rep protein, the defined coding regions of rep gene were cloned and expressed. All of the recombinant proteins except for the N-terminal 110 residues deletion mutant could bind to the double-stranded minimal binding site of replication origin (ori). In addition, the N-terminal deletion mutant lacking 110 residues exhibited mainly cytoplasmic staining in the transfected cells in contrast to the others, which localized dominantly in the nucleus, suggesting that this N-terminal domain is essential for nuclear localization. Furthermore, a series of green fluorescence proteins (GFP) containing potential nuclear localization signal (NLS) sequences were tested for their cellular distribution. The ability of the utmost 20 residues of the N-terminal region to target the GFP to the nucleus confirmed its role as a functional NLS.
Lin
Wei-Li
WL
Graduate Institute of Veterinary Microbiology, College of Veterinary Medicine, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan, ROC.
Chien
Maw-Sheng
MS
Du
Yu-Wen
YW
Wu
Pei-Ching
PC
Huang
Chienjin
C
D021581:Active Transport, Cell Nucleus; D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D017925:Circovirus / Q000235:genetics / Q000502:physiology*; D004261:DNA Replication; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D019913:Nuclear Localization Signals / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D018741:Replication Origin; D017384:Sequence Deletion; D013552:Swine; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
D019913:Nuclear Localization Signals; D014764:Viral Proteins; D049452:Green Fluorescent Proteins