Chapter 6 Posttranscriptional Gene Regulation in Kaposi's Sarcoma-Associated Herpesvirus

Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi's sarcoma, primary effusion lymphoma and some cases of multicentric Castleman's disease. To understand the pathogenesis and life cycle of KSHV, significant focus has been placed on determining how KSHV factors influence viral and cellular gene expression. The importance of transcriptional regulation by KSHV is well documented, but several KSHV posttranscriptional regulators are also essential for KSHV replication and pathogenesis. KSHV miRNAs regulate translation and stability of cellular mRNAs that may be important for tumorigenesis. The ORF57 protein has been reported to enhance several posttranscriptional processes including viral mRNA export, RNA stability and pre-mRNA splicing. SOX, Kaposin B and the PAN-ENE regulate the stability of viral or cellular transcripts. Together, these observations point to the importance of posttranscriptional regulation in KSHV. With the growing appreciation of posttranscriptional regulation in cellular gene expression, it seems likely that the list of viral posttranscriptional regulatory schemes will expand as new details of KSHV gene regulation are uncovered.