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

38 entries grouped by protein (browse by keywords)

All proteins are shown (view only 34 complete proteome entries)

5 entries

Agnoprotein (Agno)

Select_allDeselect_all
AGNO_POVJC
JC polyomavirus (JCPyV) (JCV) reference strain
AGNO_POVSM
Squirrel monkey polyomavirus reference strain

Squirrel monkey agnoprotein (Agno)

AGNO_SV40
Simian virus 40 (SV40) reference strain

Agnoprotein

AGNO_POVBA
BK polyomavirus (strain AS) (BKPyV)
AGNO_POVBK
BK polyomavirus (BKPyV) (Human polyomavirus 1)

8 entries

Large T antigen (LT) (LT-AG) (EC 3.6.4.-)

Select_allDeselect_all
LT_POVJC
JC polyomavirus (JCPyV) (JCV) reference strain
LT_POVSM
Squirrel monkey polyomavirus reference strain
LT_POVWU
WU polyomavirus (WUPyV) reference strain
LT_SV40
Simian virus 40 (SV40) reference strain
LT_POVBA
BK polyomavirus (strain AS) (BKPyV)
LT_POVBK
BK polyomavirus (BKPyV) (Human polyomavirus 1)
LT_POVKI
KI polyomavirus (isolate Stockholm 350) (KIPyV)
LT_POVMK
Murine polyomavirus (strain Kilham) (MPyV) (Murine pneumotropic virus)

1 entry

SV40 early leader protein (SELP)

SELP_SV40
Simian virus 40 (SV40) reference strain

8 entries

Small t antigen (ST) (ST-AG)

Select_allDeselect_all
ST_POVJC
JC polyomavirus (JCPyV) (JCV) reference strain
ST_POVSM
Squirrel monkey polyomavirus reference strain
ST_POVWU
WU polyomavirus (WUPyV) reference strain
ST_SV40
Simian virus 40 (SV40) reference strain
ST_POVBA
BK polyomavirus (strain AS) (BKPyV)
ST_POVBK
BK polyomavirus (BKPyV) (Human polyomavirus 1)
ST_POVKI
KI polyomavirus (isolate Stockholm 350) (KIPyV)
ST_POVMK
Murine polyomavirus (strain Kilham) (MPyV) (Murine pneumotropic virus)

8 entries

Major capsid protein VP1 (Major structural protein VP1)

Select_allDeselect_all
VP1_POVJC
JC polyomavirus (JCPyV) (JCV) reference strain
VP1_POVSM
Squirrel monkey polyomavirus reference strain
VP1_POVWU
WU polyomavirus (WUPyV) reference strain
VP1_SV40
Simian virus 40 (SV40) reference strain
VP1_POVBA
BK polyomavirus (strain AS) (BKPyV)
VP1_POVBK
BK polyomavirus (BKPyV) (Human polyomavirus 1)
VP1_POVKI
KI polyomavirus (isolate Stockholm 350) (KIPyV)
VP1_POVMK
Murine polyomavirus (strain Kilham) (MPyV) (Murine pneumotropic virus)

8 entries

Minor capsid protein VP2 (Minor structural protein VP2)

Select_allDeselect_all
VP2_POVJC
JC polyomavirus (JCPyV) (JCV) reference strain
VP2_POVSM
Squirrel monkey polyomavirus reference strain
VP2_POVWU
WU polyomavirus (WUPyV) reference strain
VP2_SV40
Simian virus 40 (SV40) reference strain
VP2_POVBA
BK polyomavirus (strain AS) (BKPyV)
VP2_POVBK
BK polyomavirus (BKPyV) (Human polyomavirus 1)
VP2_POVKI
KI polyomavirus (isolate Stockholm 350) (KIPyV)
VP2_POVMK
Murine polyomavirus (strain Kilham) (MPyV) (Murine pneumotropic virus)