title: Characterization of the hepatitis B virus preS/S region encoded transcriptional transactivator.
abstract: A transactivating function generated by carboxy-terminal truncation of the HBV envelope proteins has been recently described. To characterize the preS/S protein domains responsible for transactivation, preS1/S2/S and preS2/S 3' deletion mutants under the control of the adenoviral major late promoter were tested for their transactivating potential in cotransfection experiments using the c-myc and c-fos regulatory sequences as targets. Deletion of the carboxyterminal hydrophobic domain of the S protein and the presence of the endoplasmic reticulum insertion signal I (ER signal I) are required for the generation of the preS/S transactivating function. Multiple transcription factors binding sites (i.e., TRE, SRE, and NFkB sites) mediated the truncated preS/S-induced activation of the target regulatory sequences. The transactivation phenomenon is linked, at least in part, to the protein kinase C signaling pathway.
authors.affiliation: I Clinica Medica and Fondazione Andrea Cesalpino Policlinico Umberto I, Rome, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Natoli
authors.forename: M L
authors.initials: ML
authors.lastname: Avantaggiati
authors.forename: C
authors.initials: C
authors.lastname: Balsano
authors.forename: E
authors.initials: E
authors.lastname: De Marzio
authors.forename: D
authors.initials: D
authors.lastname: Collepardo
authors.forename: E
authors.initials: E
authors.lastname: Elfassi
authors.forename: M
authors.initials: M
authors.lastname: Levrero
mesh_terms: D003001:Cloning, Molecular; D004252:DNA Mutational Analysis; D015967:Gene Expression Regulation, Viral; D005814:Genes, Viral; D006514:Hepatitis B Surface Antigens / Q000235:genetics*; D006515:Hepatitis B virus / Q000235:genetics*; D016328:NF-kappa B / Q000502:physiology; D011493:Protein Kinase C / Q000502:physiology; D011498:Protein Precursors / Q000235:genetics*; D013329:Structure-Activity Relationship; D015534:Trans-Activators / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D015678:Viral Structural Proteins / Q000235:genetics
chemical_list: D006514:Hepatitis B Surface Antigens; D016328:NF-kappa B; D011498:Protein Precursors; D015534:Trans-Activators; D014157:Transcription Factors; D015678:Viral Structural Proteins; D011493:Protein Kinase C