title: Delineation of a core RNA element required for Kaposi's sarcoma-associated herpesvirus ORF57 binding and activity.
abstract: The Kaposi's sarcoma-associated herpesvirus (KSHV) ORF57 protein is an essential multifunctional regulator of gene expression. ORF57 interaction with RNA is necessary for ORF57-mediated posttranscriptional functions, but little is known about the RNA elements that drive ORF57-RNA specificity. Here, we investigate the cis-acting factors on the KSHV PAN RNA that dictate ORF57 binding and activity. We show that ORF57 binds directly to the 5' end of PAN RNA in KSHV-infected cells. Furthermore, we employ in vitro and cell-based assays to define a 30-nucleotide (nt) core ORF57-responsive element (ORE) that is necessary and sufficient for ORF57 binding and activity. Mutational analysis of the core ORE further suggests that a 9-nt sequence is a specific binding site for ORF57. These studies provide insight into ORF57 specificity determinants and lay a foundation for future analyses of cellular and viral ORF57 targets.
authors: Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9048, USA.
authors: Emi
authors: E
authors: Sei
authors: Nicholas K
authors: NK
authors: Conrad
mesh_terms: D001665:Binding Sites; D002460:Cell Line; D015967:Gene Expression Regulation, Viral; D057809:HEK293 Cells; D019288:Herpesvirus 8, Human / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D055029:Inverted Repeat Sequences / Q000235:genetics; D016366:Open Reading Frames / Q000235:genetics; D017354:Point Mutation; D011485:Protein Binding; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020218:Response Elements / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D012367:RNA, Viral; D014764:Viral Proteins