Kappapapillomavirus

VIRION

Non-enveloped. Small, icosahedral, about 52-55 nm in size. A single molecule of circular dsDNA is contained within the T=7 icosahedral capsid, which is composed of 72 pentamers.

GENOME

Circular dsDNA, about 8 kb in size, associated with cellular histones, encoding for 6 proteins. The E6 ORF is larger than in other genera. An uncharacterized E8 ORF is present in the early region.
On rare non-specific recombination, the viral genome can be integrated in host chromosome. This inactivates the integrated virus but can gives the host cell a replicative advantage sometimes leading to malignant tumours.

GENE EXPRESSION

Only one strand of the genome is transcribed and yield two classes of proteins expressed by alternative splicing :
a) Early Proteins: non-structural regulatory proteins (E1-E8).
b) Late Proteins: the structural proteins L1 and L2.

REPLICATION

NUCLEAR

Replication is divided in two distinct steps that are linked to the differentiation state of the host epithelial cell:

a) The plasmid replication takes place in the basal squamous epithelial cells. It corresponds to viral DNA replication in synchrony with the host cell chromosome in order to ensures an average of one viral genome per basal cell.

  1. Attachment of the viral proteins to host receptors mediates endocytosis into vesicles in the basal squamous epithelial cell.
  2. Transport to the nucleus and uncoating of the viral DNA.
  3. Early-region transcription and translation of the early proteins.
  4. Steady-state viral DNA nuclear replication. Requires the origin of DNA replication in cis and the viral E1 and E2 proteins in trans.

b) The vegetative replication, which occurs in differentiated keratinocytes. In these cells, which no longer undergo cellular DNA synthesis, there is a burst of viral DNA synthesis with active production of virions.

  1. Vegetative viral DNA synthesis.
  2. Transcription of the late region.
  3. Capsid proteins L1 and L2 synthesis.
  4. Nuclear capsid assembly and release of viruses.

Matching UniProtKB/Swiss-Prot entries

10 entries grouped by strain (browse by keywords)

All proteins are shown (view only 8 complete proteome entries)

8 entries

Cottontail rabbit papillomavirus (strain Kansas) (CRPV) (Papillomavirus sylvilagi) reference strain

Select_allDeselect_all
VL1_CRPVK Major capsid protein L1
VL2_CRPVK Minor capsid protein L2
VE1_CRPVK Replication protein E1 (EC 3.6.4.12) (ATP-dependent helicase E1)
VE5_CRPVK Probable protein E5
VE6_CRPVK Protein E6
VE4_CRPVK Probable protein E4
VE7_CRPVK Protein E7
VE2_CRPVK Regulatory protein E2

2 entries

Cottontail rabbit papillomavirus (strain Washington B) (CRPV) (Papillomavirus sylvilagi)

Select_allDeselect_all
VE7_CRPVW Protein E7
VE5_CRPVW Probable protein E5