| Product description |
Mouse monoclonal [716-281] to Papillomavirus Type 16 E7 ProteinThe HPV E7 proteins are small (HPV16 E7 comprising 98 amino acids, 15kDa), zinc binding phosphoproteins which are localised in the nucleus. They are structurally and functionally similar to the E1A protein of subgenus C adenoviruses. The first 16 amino-terminal amino acids of HPV16 E7 contain a region homologous to a segment of the conserved region 1 (CR1) of the E1A protein of subgenus C adenoviruses. The next domain, up to amino acid 37, is homologous to the entire region 2 (CR2) of E1A. Genetic studies have established that these domains are required for cell transformation in vitro, suggesting similarities in the mechanism of transformation by these viruses. The CR2 homology region contains the LXCXE motif (residues 22-26) involved in binding to the tumour suppressor protein pRb. This sequence is also present in SV40 and polyoma large T antigens. The high risk HPV E7 proteins (of, for example, types 16 and 18) have an approximately ten-fold higher affinity for pRb protein than the low risk HPV E7 proteins (of, for example, type 6). Association of the E7 protein with pRb promotes cell proliferation by the same mechanism as the E1A proteins of adenoviruses and SV40 large T antigen. Recent studies have shown that E7 promotes degradation of Rb family proteins rather than simply inhibiting their function by complex formation. The CR2 region also contains the casein kinase II phosphorylation site (residues 31 and 32). Infection with specific types of HPV has been associated with an increased risk of developing cervical neoplasia. HPV types 6 and 11 have been associated with relatively benign diseases such as genital warts but types 16 and 18 are strongly associated with cervical, vaginal, and vulvar malignancies. |
