
<ArticleTitle>The Kaposi's sarcoma-associated herpesvirus <prot>K8</prot> protein interacts with <prot>CREB-binding protein</prot> (<prot>CBP</prot>) and represses <prot>CBP</prot>-mediated transcription.</ArticleTitle>
<AbstractText>Kaposi's sarcoma-associated herpesvirus (KSHV) open reading frame K8 encodes a basic region-leucine zipper protein of 237 amino acids that homodimerizes with its bZIP domain. KSHV <prot>K8</prot> shows significant homology to the <prot>Epstein-Barr virus (EBV) immediate-early protein</prot> <prot>Zta</prot>, a key regulator in the reactivation and replication of EBV. In this study, we report that <prot>K8</prot>, like its homolog EBV <prot>Zta</prot>, interacts with cellular <prot>CREB-binding protein</prot> (<prot>CBP</prot>) in vivo and in vitro. This interaction requires the C/H3 domain of <prot>CBP</prot> and the basic region of <prot>K8</prot>. <prot>K8</prot> represses <prot>CBP</prot>-mediated transcription by competing with limited amounts of cellular <prot>CBP</prot>, exemplified by the reduced expression from the AP-1 and human immunodeficiency virus long terminal repeat promoters.</AbstractText>
