HPV Proteins

Human papillomavirus (HPV) is an infectious human virus of the skin. As most papillomaviruses do, HPV can cause papillomas, or skin lesions. low-risk HPV are much more common than high-risk HPV among humans and often do not cause any symptoms. In fact, only 18 types of HPV pose a cancer risk, mostly for anogenital cancers. Papillomaviruses are small, non-enveloped, icosahedral DNA viruses that have a diameter of 52–55 nm. The viral particles consist of a single double-stranded, circular DNA genome of about 8000 bp that contain approximately eight ORFs. The ORF can be divided into three functional parts: the early (E) region that encodes proteins (E1–E7) necessary for viral replication; the late (L) region that encodes the structural proteins (L1–L2) that are required for virion assembly; and a largely non-coding part that is referred to as the long control region (LCR), which contains cis elements that are necessary for the replication and transcription of viral DNA. The viral E proteins are transcribed from the early promoter (e.g. P97 in HPV 31) whereas the L proteins are transcribed principally from the late promoter (P742 in HPV 31).