|E1||Involved in productive HPV replication.|||
|E2||Regulates transcription from different HPV promoters.|||
|E3||Recently identified gene located in early gene region and found only in a few papillomavirus types (HPV1, 11, 16, 31, 33); its function has not been identified.|||
|E4||Represent up to 30% of total wart protein produce by HPV-1a and might serve as scaffold, transport, or structural protein.|| |
|E5||Inactivates with cellular host proteins (MHC I, Bap31); these interactions are important for the biological activity of the protein in cell transformation and evasion of the immune response.|
Play a role in regulation of transduction pathways through up-regulation of phosphatidylinositol-3′-kinase.
|[16, 17, 19] |
|E6||Inactivates the tumor suppressor protein p53, involved in the control of cell proliferation and cell response to genotoxic stress and in DNA damage.|||
|E7||Interacts with the pRb tumor suppressor protein. These interactions influence the gene expression involved in progression to S-phase of the cell cycle, such as cyclin A, cyclin D, and cyclin E genes.||[20, 22]|
|E8||Recently identified gene located in early gene region and found only in a few papillomavirus types (HPV 1, 11, 16, 31, 33). A fusion protein, E8∧E2C, functions as a negative regulator for HPV DNA replication playing a role in the control of viral copy number as well as in the stable maintenance of HPV episomes.|||
|Major capsid protein.|
Minor capsid protein.