scholarly journals Open reading frame 2 of porcine circovirus type 2 encodes a major capsid protein

2000 ◽  
Vol 81 (9) ◽  
pp. 2281-2287 ◽  
Author(s):  
Porntippa Nawagitgul ◽  
Igor Morozov ◽  
Steven R. Bolin ◽  
Perry A. Harms ◽  
Steven D. Sorden ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Gene Product ◽  
Protein S ◽  
Basic Amino Acid ◽  
Porcine Circovirus Type ◽  
Open Reading Frames ◽  
Porcine Circovirus ◽  
Structural Protein ◽  
Major Structural Protein ◽  
Orf2 Protein

Porcine circovirus 2 (PCV2), a single-stranded DNA virus associated with post-weaning multisystemic wasting syndrome of swine, has two potential open reading frames, ORF1 and ORF2, greater than 600 nucleotides in length. ORF1 is predicted to encode a replication-associated protein (Rep) essential for replication of viral DNA, while ORF2 contains a conserved basic amino acid sequence at the N terminus resembling that of the major structural protein of chicken anaemia virus. Thus far, the structural protein(s) of PCV2 have not been identified. In this study, a viral structural protein of 30 kDa was identified in purified PCV2 particles. ORF2 of PCV2 was cloned into a baculovirus expression vector and the gene product was expressed in insect cells. The expressed ORF2 gene product had a molecular mass of 30 kDa, similar to that detected in purified virus particles. The recombinant ORF2 protein self-assembled to form capsid-like particles when viewed by electron microscopy. Antibodies against the ORF2 protein were detected in samples of sera obtained from pigs as early as 3 weeks after experimental infection with PCV2. These results show that the major structural protein of PCV2 is encoded by ORF2 and has a molecular mass of 30 kDa.

scholarly journals Analysis of transcription of Porcine circovirus type 1

2002 ◽  
Vol 83 (11) ◽  
pp. 2743-2751 ◽  
Author(s):  
Annette Mankertz ◽  
Bernd Hillenbrand
Keyword(s):  
Infectious Clone ◽  
Porcine Circovirus Type ◽  
Open Reading Frames ◽  
Porcine Circovirus ◽  
Origin Of Replication ◽  
Rolling Circle Replication ◽  
Structural Protein ◽  
Rolling Circle ◽  
Rep Protein

Porcine circovirus type 1 (PCV1) contains two major open reading frames encoding the replication initiator proteins, Rep and Rep′, and the structural protein, Cap. The promoters of these two genes (P cap and P rep ) have been mapped. P cap is located within the rep open reading frame (nt 1328–1252). P rep has been mapped to the intergenic region immediately upstream of the rep gene (nt 640–796) and overlaps the origin of replication of PCV1. Although binding of both rep gene products to a fragment containing P rep and the overlapping origin of replication has been reported, only the full-length Rep protein repressed P rep , while the spliced isoform Rep′ did not. P rep repression is mediated by binding of the Rep protein to the two inner hexamers, H1 and H2, located in the origin of PCV1, whereas binding of Rep to hexamers H3 and H4 was not necessary. Use of Rep mutants indicated that the conserved rolling-circle replication domain II as well as the P loop are essential for repression of P rep . In contrast to P rep , transcription of P cap was not influenced by viral proteins. Additionally, the ratio of the rep and rep′ transcripts was analysed. Twelve hours after transfection of PK15 cells with an infectious clone of PCV1, similar amounts of both transcripts were detected, but later the amount of the two transcripts varied, indicating a balanced expression of the two rep transcripts.

scholarly journals Identification of Nuclear Localization Signals in the ORF2 Protein of Porcine Circovirus Type 3

Viruses ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1086 ◽  
Author(s):  
Chunxiao Mou ◽  
Minmin Wang ◽  
Shuonan Pan ◽  
Zhenhai Chen
Keyword(s):  
Amino Acids ◽  
Nuclear Localization ◽  
Basic Amino Acid ◽  
Subcellular Fractionation ◽  
Porcine Circovirus Type ◽  
Site Directed Mutagenesis ◽  
Porcine Circovirus ◽  
Nuclear Localization Signals ◽  
Orf2 Protein ◽  
Type 3

Porcine circovirus type 3 (PCV3) contains two major open reading frames (ORFs) and the ORF2 gene encodes the major structural capsid protein. In this study, nuclear localization of ORF2 was demonstrated by fluorescence observation and subcellular fractionation assays in ORF2-transfected PK-15 cells. The subcellular localization of truncated ORF2 indicated that the 38 N-terminal amino acids were responsible for the nuclear localization of ORF2. The truncated and site-directed mutagenesis of this domain were constructed, and the results demonstrated that the basic amino acid residues at positions 8–32 were essential for the strict nuclear localization. The basic motifs 8RRR-R-RRR16 and 16RRRHRRR22 were further shown to be the key functional nucleolar localization signals that guide PCV3 ORF2 into nucleoli. Furthermore, sequence analysis showed that the amino acids of PCV3 nuclear localization signals were highly conserved. Overall, this study provides insight into the biological and functional characteristics of the PCV3 ORF2 protein.

Porcine bocaviruses: genetic analysis and prevalence in Chinese swine population

2011 ◽  
Vol 139 (10) ◽  
pp. 1581-1586 ◽  
Author(s):  
H. B. ZHANG ◽  
L. HUANG ◽  
Y. J. LIU ◽  
T. LIN ◽  
C. Q. SUN ◽  
...  
Keyword(s):  
Porcine Circovirus Type ◽  
Open Reading Frames ◽  
Porcine Circovirus ◽  
Respiratory Syndrome Virus ◽  
Mixed Infections ◽  
Detection Rates ◽  
Swine Population ◽  
Swine Herds ◽  
Reading Frames

SUMMARYIn members of theBocavirusgenus, that contain three open reading frames (ORFs) of the Parvovirinae subfamily, porcine bocaviruses (PoBoVs) exhibit the most genetic diversity. Based on the ORF2-encoded viral protein (VP1) classification, the six reported porcine bocaviruses were grouped into four species: PoBoV1 (porcine boca-like virus or PBoLV), PoBoV2 (porcine parvovirus 4 or PPV4), PoBoV3 (PBoV1/PBoV2) and PoBoV4 (6V/7V), with PoBoV3 and PoBoV4 each having two genotype viruses. All four PoBoV species were detected in the 166 samples collected in 2010 from swine herds located in ten provinces of China. The detection rates for PoBoV1-4 were 28·9%, 6·6%, 19·3% and 39·7%, respectively. The co-infection combinations involving these six porcine bocaviruses in the collected samples were very complex. Furthermore, mixed infections with viruses from other families (porcine reproductive and respiratory syndrome virus, classic swine fever virus and porcine circovirus type 2) were also detected.

scholarly journals COMPLETE GENOME SEQUENCE OF PORCINE CIRCOVIRUS TYPE 2 UKRAINIAN ISOLATES

2016 ◽  
Vol 72 (2) ◽  
pp. 5-8
Author(s):  
L. Dudar ◽  
V. Polischuk ◽  
L. Budzanivska ◽  
Gyula Balka ◽  
Attila Csagola
Keyword(s):  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Porcine Circovirus Type ◽  
Postweaning Multisystemic Wasting Syndrome ◽  
Porcine Circovirus Type 2 ◽  
Open Reading Frames ◽  
Porcine Circovirus ◽  
Wasting Syndrome

Porcine circovirus type 2 (PCV2) is associated with distinct syndromes and diseases in swine, collectively known as porcine circovirus-associated diseases (PCVAD), which include postweaning multisystemic wasting syndrome (PMWS), PCV2-associated pneumonia as a part of the porcine respiratory disease complex (PRDC), PCV2-associated enteritis, PCV2-associated reproductive failure, and porcine dermatitis and nephropathy syndrome (PDNS) (1–3). PCV2-infection is widespread and essentially all pig herds are infected with PCV2. Porcine circovirus 2 (PCV2), a member of the genus Circovirus in the family Circoviridae, is a very small single-stranded negative-sense DNA virus of approximately 1.7 kb (4). The genome of PCV2 encodes three major open reading frames (ORFs) encoding the replicase proteins (ORF1), the viral capsid protein (ORF2), and a protein with suggested apoptotic activity (ORF3) (5). Previous reports showed that there were five PCV2 genotypes, including PCV2a, PCV2b, PCV2c, PCV2d, and PCV2e (6– 9). Here, we report the complete genome sequence of Ukrainian PCV2 isolates from different regions of Ukraine.

scholarly journals Fusion Expression and Immune Effect of PCV2 Cap Protein Tandem Multiantigen Epitopes with CD154/GM-CSF

2021 ◽  
Vol 8 (10) ◽  
pp. 211
Author(s):  
Qian Mao ◽  
Weijian Zhang ◽  
Shengming Ma ◽  
Zilong Qiu ◽  
Bingke Li ◽  
...  
Keyword(s):  
Fusion Proteins ◽  
Porcine Circovirus Type ◽  
The Body ◽  
Porcine Circovirus ◽  
Structural Protein ◽  
Specific Antibodies ◽  
Humoral And Cellular Immunity ◽  
Viral Loads ◽  
Gm Csf ◽  
Cellular Immune

Porcine circovirus associated diseases (PCVAD) is a contagious disease of swine caused by porcine circovirus type 2 (PCV2). The capsid protein (Cap) is the sole structural protein and the main antigen of PCV2. Cap is the principal immunogenic protein and induces humoral and cellular immunity. CD154 and GM-CSF are immune adjuvants that enhance responses to vaccines. However, whether these two cellular molecules could produce an enhanced effect in PCV2 vaccines still needs to be further studied. The results of PCR and restriction enzyme showed that the recombinant lentiviral plasmids pCDH-TB-Cap, pCDH-TB-Cap-CD154 and pCDH-TB-Cap were successfully constructed. Western blot and IFA showed that the three fusion proteins TB-Cap, TB-Cap-CD154 and TB-Cap-GM-CSF were stably expressed in CHO-K1 cells. Indirect ELISA assay showed that mice immunized with TB-Cap-CD154 and TB-Cap-GM-CSF fusion proteins produced higher PCV2-specific antibodies than mice immunized with the TB-Cap and a commercial vaccine (p < 0.0001). Moreover, lymphocyte proliferation and flow cytometry showed that the cellular immune response of each immune group was significantly enhanced (p < 0.0001). After PCV2 challenge, the results revealed that the viral loads in serum, lung and kidney of all vaccinated groups were significantly lower than the PBS group (p < 0.0001). The transcription levels of IL-2, IFN-gamma, IL-4 and IL-10 cytokines in the TB-Cap, TB-Cap-CD154 and TB-Cap-GM-CSF groups were significantly higher than those in the PBS and recombinant vaccine groups (p < 0.0001). These results indicated that CD154 and GM-CSF could enhance the ability of TB-Cap protein to induce the body to produce PCV2 specific antibodies and increase the transcription level of cytokines. Thus, CD154 and GM-CSF molecules were a powerful immunoadjuvant for PCV2 subunit vaccines. The novel TB-Cap-CD154 and TB-Cap-GM-CSF subunit vaccine has the potential to be used for the prevention and control of PCVAD.

scholarly journals Nuclear Localization of the ORF2 Protein Encoded by Porcine Circovirus Type 2

Virology ◽  
2001 ◽  
Vol 285 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Qiang Liu ◽  
Suresh K. Tikoo ◽  
Lorne A. Babiuk
Keyword(s):  
Nuclear Localization ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Porcine Circovirus ◽  
Orf2 Protein
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