title: An RNA activator of subgenomic mRNA1 transcription in tomato bushy stunt virus.
abstract: Many (+)-strand RNA viruses transcribe small subgenomic (sg) mRNAs that allow for regulated expression of a subset of their genes. Tomato bushy stunt virus (TBSV) transcribes two such messages and here we report the identification of a long-distance RNA*RNA interaction that is essential for the efficient accumulation of capsid protein-encoding sg mRNA1. The relevant base pairing interaction occurs within the TBSV RNA genome between a 7-nucleotide (nt) long sequence, separated by just 3 nt from the downstream sg mRNA1 initiation site, and a complementary sequence positioned some approximately 1000 nt further upstream. Analyses of this interaction indicate that it (i) functions in the (+)-strand, (ii) modulates both (+)- and (-)-strand sg mRNA1 accumulation, (iii) specifically regulates the accumulation of sg mRNA1 (-)-strands, (iv) controls sg mRNA1 expression from an ectopic transcriptional initiation site, (v) may occur in cis and, and (vi) could nucleate the formation of a more complex RNA structure. These data are most consistent with a role for this interaction in regulating sg mRNA1 accumulation at the level of transcription.
authors.affiliation: Department of Biology, York University, Toronto, Ontario M3J 1P3, Canada.
authors.forename: Il-Ryong
authors.initials: IR
authors.lastname: Choi
authors.forename: K Andrew
authors.initials: KA
authors.lastname: White
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D015967:Gene Expression Regulation, Viral; D016679:Genome, Viral; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009690:Nucleic Acid Conformation; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics*; D017864:Tombusvirus / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D017931:DNA Primers; D012333:RNA, Messenger; D012367:RNA, Viral