title: Mutational analysis of bovine leukemia virus Rex: identification of a dominant-negative inhibitor.
abstract: The Rex proteins of the delta-retroviruses act to facilitate the export of intron-containing viral RNAs. The Rex of bovine leukemia virus (BLV) is poorly characterized. To gain a better understanding of BLV Rex, we generated a reporter assay to measure BLV Rex function and used it to screen a series of point and deletion mutations. Using this approach, we were able to identify the nuclear export signal of BLV Rex. Further, we identified a dominant-negative form of BLV Rex. Protein localization analysis revealed that wild-type BLV Rex had a punctate nuclear localization and was associated with nuclear pores. In contrast, the dominant-negative BLV Rex mutation had a diffuse nuclear localization and no nuclear pore association. Overexpression of the dominant-negative BLV Rex altered the localization of the wild-type protein. This dominant-negative derivative of BLV Rex could be a useful tool to test the concept of intracellular immunization against viral infection in a large animal model.
authors.affiliation: Department of Microbiology and Immunology, University of Illinois at Chicago, 835 S. Wolcott, Chicago, IL 60612, USA.
authors.forename: Eun-A
authors.initials: EA
authors.lastname: Choi
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Hope
mesh_terms: D021581:Active Transport, Cell Nucleus; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002460:Cell Line; D004279:DNA, Viral / Q000235:genetics; D016370:Gene Products, rex / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000502:physiology; D017930:Genes, Reporter; D005814:Genes, Viral; D006367:HeLa Cells; D006801:Humans; D001909:Leukemia Virus, Bovine / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology; D008969:Molecular Sequence Data; D009154:Mutation; D017354:Point Mutation; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid
chemical_list: D004279:DNA, Viral; D016370:Gene Products, rex