title: Positive and negative regulation in the promoter of the ORF46 gene of Kaposi's sarcoma-associated herpesvirus.
abstract: The ORF46 gene of Kaposi's sarcoma-associated herpesvirus (KSHV) encodes uracil DNA glycosylase, an enzyme involved in DNA repair. In this study, we show that the transcriptional start site of the ORF46 gene is located at nucleotide 69,425 of the viral genome and ORF50 protein, a latent-lytic switch transactivator, activates the ORF46 promoter via RBP-Jκ protein. Three consensus RBP-Jκ-binding sites found in the ORF46 promoter are critical for the binding of RBP-Jκ protein and conferring the ORF50 responsiveness. In addition, a negative regulatory region has been determined in the ORF46 promoter, which mediates the suppression of the ORF50 responsiveness. The functional negative region of the ORF46 promoter is mainly composed of the Sp1-binding sites. Like the negative region of the ORF46 promoter, addition of Sp1-binding sequences alone in an ORF50-responsive promoter efficiently confers the suppression of the ORF50 responsiveness. Furthermore, sodium butyrate, a pleiotropic inducing agent for the KSHV lytic cycle, is able to relieve the negative regulation of the ORF46 promoter in the latently KSHV-infected cells. The identification of multiple positive and negative cis-acting regulatory elements in the viral promoters emphasizes the elaborate controls in the KSHV lytic cycle, which ensure the adequate expression of each viral lytic gene.
authors.affiliation: Graduate Institute of Clinical Medical Sciences, Chang-Gung University, Taoyuan, Taiwan; Departments of Pediatric Surgery, Chang-Gung Memorial Hospital, Chiayi, Taiwan.
authors.forename: Shie-Shan
authors.initials: SS
authors.lastname: Wang
authors.forename: Pey-Jium
authors.initials: PJ
authors.lastname: Chang
authors.forename: Lee-Wen
authors.initials: LW
authors.lastname: Chen
authors.forename: Li-Yu
authors.initials: LY
authors.lastname: Chen
authors.forename: Chien-Hui
authors.initials: CH
authors.lastname: Hung
authors.forename: Jieh-Yuan
authors.initials: JY
authors.lastname: Liou
authors.forename: Ju-Bei
authors.initials: JB
authors.lastname: Yen
mesh_terms: D001665:Binding Sites; D045744:Cell Line, Tumor; D015967:Gene Expression Regulation, Viral; D019288:Herpesvirus 8, Human / Q000201:enzymology / Q000235:genetics*; D006801:Humans; D017874:Immediate-Early Proteins / Q000378:metabolism*; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D016329:Sp1 Transcription Factor / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism*; D024363:Transcription Initiation Site; D051981:Uracil-DNA Glycosidase / Q000096:biosynthesis*
chemical_list: D017874:Immediate-Early Proteins; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein; C417604:Rta protein, Human herpesvirus 8; D016329:Sp1 Transcription Factor; D015534:Trans-Activators; D051981:Uracil-DNA Glycosidase