title: The role of the E1 and E2 proteins in the replication of human papillomavirus type 31b.
abstract: Using transient assays, the cis and trans requirements for human papillomavirus type 31b (HPV-31b) replication in transformed and primary keratinocytes have been determined. We demonstrate that expression of both the E1 and E2 open reading frames are necessary and sufficient for replication of a plasmid construct containing a genomic 291-bp fragment in both cell types. The roles of the E1 and E2 proteins in replication were further examined by overexpressing the gene products in a glutathione-S-transferase bacterial expression system. In addition to a full-length E1 protein, a truncated E1 protein (E1*) which consisted of the amino-terminal 268 aa was synthesized. Both E1 and E1* were found to complex efficiently with the E2 protein in vivo and in vitro. In addition, site-specific DNA binding by both the E2 and E1 proteins to HPV-31b origin containing DNA was observed. The E1* protein, however, failed to bind HPV-31b DNA specifically and could not cooperate with E2 for replication in transient assays. DNase I footprinting demonstrated that the E1 protein of HPV-31b bound to an A/T-rich region (nucleotides 7905-24) which shares similarities with the binding site for the bovine papillomavirus type 1 (BPV-1) E1 protein. These studies describe both similarities and differences in the requirements for replication of HPV-31b and BPV-1.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Chicago, Illinois 60637.
authors.forename: M G
authors.initials: MG
authors.lastname: Frattini
authors.forename: L A
authors.initials: LA
authors.lastname: Laimins
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D052688:Bovine papillomavirus 1 / Q000502:physiology; D002294:Carcinoma, Squamous Cell / Q000821:virology; D004261:DNA Replication; D016679:Genome, Viral; D006801:Humans; D008969:Molecular Sequence Data; D009856:Oncogene Proteins, Viral / Q000502:physiology*; D027383:Papillomaviridae / Q000235:genetics / Q000502:physiology*; D014779:Virus Replication
chemical_list: D009856:Oncogene Proteins, Viral