INTERACTION OF PAPILLOMAVIRUS E6 ONCOPROTEINS WITH A PUTATIVE CALCIUM-BINDING PROTEIN

Human papillomaviruses (HPVs) are associated with the majority of cerv ical cancers and encode a transforming protein, E6, that interacts wit h the tumor suppressor protein p53. Because E6 has p53-independent tra nsforming activity, the yeast two-hybrid system was used to search for other EG-binding proteins. One such protein, E6BP, interacted with ca ncer-associated HPV E6 and with bovine papillomavirus type 1 (BPV-1) E 6. The transforming activity of BPV-1 E6 mutants correlated with their E6BP-binding ability. E6BP is identical to a putative calcium-binding protein, ERC-55, that appears to be localized in the endoplasmic reti culum.