Positive and negative regulation in the promoter of the ORF46 gene of Kaposi's sarcoma-associated herpesvirus

► Multiple positive and negative control elements are present in the ORF46 promoter. ► Activation of the ORF46 promoter by ORF50 protein is mediated through RBP-Jκ. ► The negative elements in the ORF46 promoter suppress ORF50 responsiveness. ► The negative region of the ORF46 promoter contains Sp1-binding sequences. ► Sodium butyrate can relieve the negative regulation of the ORF46 promoter.