Inhibition of Human Papillomavirus DNA Replication by Small Molecule Antagonists of the E1-E2 Protein Interaction

• Published in: The Journal of biological chemistry Vol. 278; no. 29; pp. 26765 - 26772
• Main Authors: White, Peter W., Titolo, Steve, Brault, Karine, Thauvette, Louise, Pelletier, Alex, Welchner, Ewald, Bourgon, Lise, Doyon, Louise, Ogilvie, William W., Yoakim, Christiane, Cordingley, Michael G., Archambault, Jacques
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 18.07.2003; American Society for Biochemistry and Molecular Biology
• Subjects: Amino Acid Substitution; Animals; Base Sequence; Binding Sites; CHO Cells; Cottontail rabbit papillomavirus - drug effects; Cottontail rabbit papillomavirus - genetics; Cottontail rabbit papillomavirus - metabolism; Cricetinae; DNA Replication - drug effects; DNA, Viral - biosynthesis; DNA, Viral - genetics; DNA-Binding Proteins - antagonists & inhibitors; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Humans; Oncogene Proteins, Viral - antagonists & inhibitors; Oncogene Proteins, Viral - genetics; Oncogene Proteins, Viral - metabolism; Papillomaviridae - drug effects; Papillomaviridae - genetics; Papillomaviridae - metabolism; Protein Binding - drug effects; Rabbits; Recombinant Proteins - antagonists & inhibitors; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Transcriptional Activation; Transfection; Viral Proteins - antagonists & inhibitors; Viral Proteins - genetics; Viral Proteins - metabolism
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M303608200

Human papillomavirus (HPV) DNA replication is initiated by recruitment of the E1 helicase by the E2 protein to the viral origin. Screening of our corporate compound collection with an assay measuring the cooperative binding of E1 and E2 to the origin identified a class of small molecule inhibitors of the protein interaction between E1 and E2. Isothermal titration calorimetry and changes in protein fluorescence showed that the inhibitors bind to the transactivation domain of E2, the region that interacts with E1. These compounds inhibit E2 of the low risk HPV types 6 and 11 but not those of high risk HPV types or of cottontail rabbit papillomavirus. Functional evidence that the transactivation domain is the target of inhibition was obtained by swapping this domain between a sensitive (HPV11) and a resistant (cottontail rabbit papillomavirus) E2 type and by identifying an amino acid substitution, E100A, that increases inhibition by ∼10-fold. This class of inhibitors was found to antagonize specifically the E1-E2 interaction in vivo and to inhibit HPV DNA replication in transiently transfected cells. These results highlight the potential of the E1-E2 interaction as a small molecule antiviral target.