Betapolyomavirus

VIRION

Non-enveloped capsid with a T=7d icosahedral symmetry, about 50 nm in diameter.

GENOME

Circular dsDNA about 5 kb in size, associated with cellular histones in a chromatin-like complex. Encodes for 5-9 proteins.
On rare non-specific recombination, the viral genome can be integrated in host chromosome. This inactivates the integrated virus but can give the host cell a replicative advantage sometimes leading to malignant tumours.

GENE EXPRESSION

Transcription is nuclear, in two phases; early (replication), late (virion assembly/exit). 5-9 proteins are expressed from the two pre-MRNA by alternative splicing. All genes are transcribed by host RNA pol II.

REPLICATION

NUCLEAR

  1. Attachment of the viral proteins to host receptors triggers lipid-mediated endocytosis of the virus into the host cell.
  2. Virion transits through endoplasmic reticulum where host protein disulfide isomerases rearrange its capsid structure
  3. Export of misfolded virion to the cytoplasm possibly through host ERAD pathway
  4. Loss of VP1 in the low-calcium conditions of the cytosol
  5. Import of genomic DNA into host nucleus.
  6. Transcription of early genes (LT and sT genes)
  7. Replication of the DNA genome in the nucleus.
  8. Transcription of late genes encoding for structural proteins (VP1, VP2 and VP3).
  9. Assembly of new virions in nuclear viral factories.
  10. Virions are released by lysis of the cell.

Host-virus interaction

Cell-cycle modulation

The large T antigen binds to host key cell cycle regulators retinoblastoma protein RB1/pRb and TP53 and induces the disassembly of host E2F1 transcription factors from RB1, thus promoting transcriptional activation of E2F1-regulated S-phase genes.

Matching UniProtKB/Swiss-Prot entries

46 entries grouped by strain (browse by keywords)

All proteins are shown (view only 42 complete proteome entries)

6 entries

Simian virus 40 (SV40) reference strain

Select_allDeselect_all
SELP_SV40 SV40 early leader protein (SELP)
LT_SV40 Large T antigen (LT) (LT-AG) (EC 3.6.4.-)
AGNO_SV40 Agnoprotein
VP2_SV40 Minor capsid protein VP2 (Minor structural protein VP2)
VP1_SV40 Major capsid protein VP1 (Major structural protein VP1)
ST_SV40 Small t antigen (ST) (ST-AG)

5 entries

BK polyomavirus (BKPyV) (Human polyomavirus 1) reference strain

Select_allDeselect_all
LT_POVBK Large T antigen (LT) (LT-AG) (EC 3.6.4.-)
AGNO_POVBK Agnoprotein (Agno)
VP2_POVBK Minor capsid protein VP2 (Minor structural protein VP2)
VP1_POVBK Major capsid protein VP1 (Major structural protein VP1)
ST_POVBK Small t antigen (ST) (ST-AG)

5 entries

JC polyomavirus (JCPyV) (JCV) reference strain

Select_allDeselect_all
LT_POVJC Large T antigen (LT) (LT-AG) (EC 3.6.4.-)
AGNO_POVJC Agnoprotein (Agno)
VP2_POVJC Minor capsid protein VP2 (Minor structural protein VP2)
ST_POVJC Small t antigen (ST) (ST-AG)
VP1_POVJC Major capsid protein VP1 (Major structural protein VP1)

5 entries

Squirrel monkey polyomavirus reference strain

Select_allDeselect_all
LT_POVSM Large T antigen (LT) (LT-AG) (EC 3.6.4.-)
AGNO_POVSM Squirrel monkey agnoprotein (Agno)
VP2_POVSM Minor capsid protein VP2 (Minor structural protein VP2)
ST_POVSM Small t antigen (ST) (ST-AG)
VP1_POVSM Major capsid protein VP1 (Major structural protein VP1)

4 entries

WU polyomavirus (WUPyV) reference strain

Select_allDeselect_all
LT_POVWU Large T antigen (LT) (LT-AG) (EC 3.6.4.-)
VP1_POVWU Major capsid protein VP1 (Major structural protein VP1)
VP2_POVWU Minor capsid protein VP2 (Minor structural protein VP2)
ST_POVWU Small t antigen (ST) (ST-AG)

5 entries

BK polyomavirus (strain AS) (BKPyV)

Select_allDeselect_all
LT_POVBA Large T antigen (LT) (LT-AG) (EC 3.6.4.-)
AGNO_POVBA Agnoprotein (Agno)
VP1_POVBA Major capsid protein VP1 (Major structural protein VP1)
VP2_POVBA Minor capsid protein VP2 (Minor structural protein VP2)
ST_POVBA Small t antigen (ST) (ST-AG)

4 entries

KI polyomavirus (isolate Stockholm 350) (KIPyV)

Select_allDeselect_all
LT_POVKI Large T antigen (LT) (LT-AG) (EC 3.6.4.-)
VP2_POVKI Minor capsid protein VP2 (Minor structural protein VP2)
ST_POVKI Small t antigen (ST) (ST-AG)
VP1_POVKI Major capsid protein VP1 (Major structural protein VP1)

4 entries

KI polyomavirus (isolate Stockholm 380) (KIPyV)

Select_allDeselect_all
LT_POVK3 Large T antigen (LT) (LT-AG) (EC 3.6.4.-)
VP2_POVK3 Minor capsid protein VP2 (Minor structural protein VP2)
VP1_POVK3 Major capsid protein VP1 (Major structural protein VP1)
ST_POVK3 Small t antigen (ST) (ST-AG)

4 entries

KI polyomavirus (isolate Stockholm 60) (KIPyV)

Select_allDeselect_all
LT_POVK6 Large T antigen (LT) (LT-AG) (EC 3.6.4.-)
VP1_POVK6 Major capsid protein VP1 (Major structural protein VP1)
VP2_POVK6 Minor capsid protein VP2 (Minor structural protein VP2)
ST_POVK6 Small t antigen (ST) (ST-AG)

4 entries

Murine polyomavirus (strain Kilham) (MPyV) (Murine pneumotropic virus)

Select_allDeselect_all
LT_POVMK Large T antigen (LT) (LT-AG) (EC 3.6.4.-)
VP1_POVMK Major capsid protein VP1 (Major structural protein VP1)
VP2_POVMK Minor capsid protein VP2 (Minor structural protein VP2)
ST_POVMK Small t antigen (ST) (ST-AG)