title: Tomato bushy stunt virus genomic RNA accumulation is regulated by interdependent cis-acting elements within the movement protein open reading frames.
abstract: This study on Tomato bushy stunt virus identified and defined three previously unknown regulatory sequences involved in RNA accumulation that are located within the 3'-proximal nested movement protein genes p22 and p19. The first is a 16-nucleotide (nt) element termed III-A that is positioned at the very 3' end of p22 and is essential for RNA accumulation. Approximately 300 nt upstream of III-A resides an approximately 80-nt inhibitory element (IE) that is obstructive to replication only in the absence of a third regulatory element of approximately 30 nt (SUR-III) that is positioned immediately upstream of III-A. Inspection of the nucleotide sequences predicted that III-A and SUR-III can form looped hairpins. A comparison of different tombusviruses showed, in each case, conservation for potential base pairing between the two predicted hairpin-loops. Insertion of a spacer adjacent to the predicted hairpins had no or a minimal effect on RNA accumulation, whereas an insertion in the putative III-A loop abolished genomic RNA multiplication. We conclude that the sequences composing the predicted III-A and SUR-III hairpin-loops are crucial for optimal RNA accumulation and that the inhibitory effect of IE surfaces when the alleged interaction between SUR-III and III-A is disturbed.
authors.affiliation: Department of Plant Pathology and Microbiology, Intercollegiate Faculty of Virology, Texas A&M University, College Station, TX 77843, USA.
authors.forename: Jong-Won
authors.initials: JW
authors.lastname: Park
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Desvoyes
authors.forename: Herman B
authors.initials: HB
authors.lastname: Scholthof
mesh_terms: D005809:Genes, Regulator / Q000502:physiology*; D016254:Mutagenesis, Insertional; D016366:Open Reading Frames; D053830:Plant Viral Movement Proteins; D012367:RNA, Viral / Q000737:chemistry / Q000378:metabolism*; D017864:Tombusvirus / Q000235:genetics*; D014764:Viral Proteins / Q000235:genetics*
chemical_list: D053830:Plant Viral Movement Proteins; D012367:RNA, Viral; D014764:Viral Proteins