Table 1:

Summary of the functions of Human Papilloma Virus genes. Oncogenes E6 and E7 are summarized in Figure 2. E, early genes and L, late genes.

Viral gene	Function
E1	• ATP-dependent helicase essential for viral genome replication  • Recruits host cell DNA replication proteins
E2	• Activates or represses viral gene transcription  • Initiates viral DNA replication by interacting with E1  • Tethers viral genomes to host chromosomes in mitosis
E4	Expressed during later stages of infection  • Amplifies viral genome  • Role in viral synthesis  • Promotes and contributes to virion release
E5	• Activates mitogenic signaling pathways  • Inhibits MHC I expression  • suppression of IFN-κ  • modulates transit of signaling proteins through ER  • Alters activity of EGFR  • Enhances transforming abilities of E6 and E7  • Prevents keratinocyte differentiation
L1	• Major viral capsid protein
L2	• Minor viral capsid protein, involved in encapsidation of viral DNA  • Associates with viral DNA to assist with trafficking to host nucleus