Circoviridae

VIRION

Non-enveloped, round, T=1 icosahedral symmetry, about 20 nm in diameter. The capsid consists of 12 pentagonal trumpet-shaped pentamers.

GENOME

Monopartite, circular, ssDNA genome of about 1.8 to 3.8 kb.
The genome is replicated through double-stranded intermediates. The replication (Rep) protein initiates rolling circle replication.

GENE EXPRESSION

One or two mRNAs encode for the Rep, capsid, and possibly others proteins. Some mRNA can undergo alternative splicing.

REPLICATION

NUCLEAR

  1. Virus penetrates into the host cell.
  2. Uncoating, the viral ssDNA genome penetrates into the nucleus.
  3. Viral ssDNA is converted into dsDNA with the participation of cellular factors. dsDNA transcription gives rise to viral mRNAs.
  4. Viral mRNAs are translated to produce viral proteins.
  5. Replication may be mediated by a Rep protein, and would occur by rolling circle replication producing ssDNA genomes.
  6. These newly synthesized ssDNA can either
    a) be converted to dsDNA and serve as a template for transcription/replication
    b) be encapsidated by capsid protein and form virions released by cell lysis.

Host-virus interaction

Autophagy modulation

Cap protein of PCV2 induces activation of host autophagy in order to enhance its own replication .

Apoptosis modulation

PCV2 ORF3-encoded protein induces apoptosis by activating caspase-8 and caspase-3 pathways . This protein may be a candidate for PML bodies inhibition which is essential for nuclear virus replication in mammals.

Matching UniProtKB/Swiss-Prot entries

40 entries grouped by strain (browse by keywords)

All proteins are shown (view only 39 complete proteome entries)

7 entries

Beak and feather disease virus (BFDV) reference strain

Select_allDeselect_all
CAPSD_BFDV Capsid protein
ORF4_BFDV Uncharacterized protein ORF4
ORF5_BFDV Uncharacterized protein ORF5
ORF3_BFDV Uncharacterized protein ORF3
ORF6_BFDV Uncharacterized protein ORF6
ORF7_BFDV Uncharacterized protein ORF7
REP_BFDV Replication-associated protein (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) (ATP-dependent helicase Rep) ...

3 entries

Chicken anemia virus (isolate Germany Cuxhaven-1) (CAV) reference strain

Select_allDeselect_all
CAPSD_CAVC1 Capsid protein (CA1) (Coat protein)
VP3_CAVC1 Apoptin
VP2_CAVC1 Dual specificity protein phosphatase VP2 (EC 3.1.3.16) (EC 3.1.3.48)

2 entries

Canary circovirus (CaCV) reference strain

Select_allDeselect_all
CAPSD_CACV Probable capsid protein
REP_CACV Replication-associated protein (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) (ATP-dependent helicase Rep) ...

2 entries

Porcine circovirus 1 (isolate China) (PCV1) reference strain

Select_allDeselect_all
CAPSD_PCV1C Capsid protein
REP_PCV1C Replication-associated protein (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) (ATP-dependent helicase Rep) ...

5 entries

Pigeon circovirus (PiCV) (Columbid circovirus)

Select_allDeselect_all
CAPSD_PICV Probable capsid protein
ORFC3_PICV Uncharacterized protein ORFC3
ORFC4_PICV Uncharacterized protein ORFC4
ORFC2_PICV Uncharacterized protein ORFC2
REP_PICV Replication-associated protein (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) (ATP-dependent helicase Rep) ...

4 entries

Goose circovirus (GoCV)

Select_allDeselect_all
CAPSD_GOCV Probable capsid protein
ORFC2_GOCV Uncharacterized protein ORFC2
ORFV2_GOCV Uncharacterized protein ORFV2
REP_GOCV Replication-associated protein (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) (ATP-dependent helicase Rep) ...

4 entries

Porcine circovirus 2 (PCV2)

Select_allDeselect_all
CAPSD_PCV2 Capsid protein
NS0_PCV2 Protein NS0
ORF3_PCV2 Protein ORF3
REP_PCV2 Replication-associated protein (EC 2.7.7.-) (EC 3.1.21.-) (EC 3.6.1.3) (ATP-dependent helicase Rep) ...

3 entries

Chicken anemia virus (isolate Australia/CAU269-7/2000) (CAV)

Select_allDeselect_all
CAPSD_CAVCA Capsid protein (CA1) (Coat protein)
VP2_CAVCA Dual specificity protein phosphatase VP2 (EC 3.1.3.16) (EC 3.1.3.48)
VP3_CAVCA Apoptin

3 entries

Chicken anemia virus (isolate Japan 82-2) (CAV)

Select_allDeselect_all
CAPSD_CAV82 Capsid protein (CA1) (Coat protein)
VP3_CAV82 Apoptin
VP2_CAV82 Dual specificity protein phosphatase VP2 (EC 3.1.3.16) (EC 3.1.3.48)

3 entries

Chicken anemia virus (isolate USA 26p4) (CAV)

Select_allDeselect_all
CAPSD_CAV26 Capsid protein (CA1) (Coat protein)
VP2_CAV26 Dual specificity protein phosphatase VP2 (EC 3.1.3.16) (EC 3.1.3.48)
VP3_CAV26 Apoptin

3 entries

Chicken anemia virus (isolate USA CIA-1) (CAV)

Select_allDeselect_all
CAPSD_CAVCI Capsid protein (CA1) (Coat protein)
VP3_CAVCI Apoptin
VP2_CAVCI Dual specificity protein phosphatase VP2 (EC 3.1.3.16) (EC 3.1.3.48)

1 entry

Chicken anemia virus (isolate Australia) (CAV)

CAPSD_CAVAU Capsid protein (CA1) (Coat protein)