Alphapolyomavirus

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 5-6 proteins.

GENE EXPRESSION

Transcription is nuclear, in two phases; early (replication), late (virion assembly/exit). 5-6 proteins are expressed from the two pre-MRNA by alternative splicing. All genes are transcribed by host RNA pol II.

REPLICATION

NUCLEAR

  1. Attachement 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.

Matching UniProtKB/Swiss-Prot entries

21 entries grouped by strain (browse by keywords)

All proteins are shown (view only 18 complete proteome entries)

4 entries

Hamster polyomavirus (HaPyV) (Mesocricetus auratus polyomavirus 1) reference strain

Select_allDeselect_all
LT_POVHA Large T antigen (LT) (LT-AG) (EC 3.6.4.-)
MT_POVHA Middle T antigen (MT) (MT-AG)
ST_POVHA Small t antigen (ST) (ST-AG)
VP2_POVHA Minor capsid protein VP2 (Minor structural protein VP2)

5 entries

Murine polyomavirus (strain A2) (MPyV) reference strain

Select_allDeselect_all
LT_POVMA Large T antigen (LT) (LT-AG) (EC 3.6.4.-)
MT_POVMA Middle T antigen (MT) (MT-AG)
ST_POVMA Small t antigen (ST) (ST-AG)
VP2_POVMA Minor capsid protein VP2 (Minor structural protein VP2)
VP1_POVMA Major capsid protein VP1 (Major structural protein VP1)

1 entry

Hamster polyomavirus (HaPyV) (Mesocricetus auratus polyomavirus 1)

VP1_POVHA Major capsid protein VP1 (Major structural protein VP1)

5 entries

Murine polyomavirus (strain 3) (MPyV)

Select_allDeselect_all
LT_POVM3 Large T antigen (LT) (LT-AG) (EC 3.6.4.-)
MT_POVM3 Middle T antigen (MT) (MT-AG)
ST_POVM3 Small t antigen (ST) (ST-AG)
VP1_POVM3 Major capsid protein VP1 (Major structural protein VP1)
VP2_POVM3 Minor capsid protein VP2 (Minor structural protein VP2)

5 entries

Murine polyomavirus (strain Crawford small-plaque) (MPyV)

Select_allDeselect_all
LT_POVMC Large T antigen (LT) (LT-AG) (EC 3.6.4.-)
MT_POVMC Middle T antigen (MT) (MT-AG)
ST_POVMC Small t antigen (ST) (ST-AG)
VP2_POVMC Minor capsid protein VP2 (Minor structural protein VP2)
VP1_POVMC Major capsid protein VP1 (Major structural protein VP1)

1 entry

Murine polyomavirus (strain P16 small-plaque) (MPyV)

VP1_POVMP Capsid protein VP1