title: Sendai virus RNA polymerase scanning for mRNA start sites at gene junctions.
abstract: Mini-genomes expressing two reporter genes and a variable gene junction were used to study Sendai virus RNA polymerase (RdRp) scanning for the mRNA start signal of the downstream gene (gs2). We found that RdRp could scan the template efficiently as long as the initiating uridylate of gs2 (3' UCCCnnUUUC) was preceded by the conserved intergenic region (3' GAA) and the last 3 uridylates of the upstream gene end signal (ge1; 3' AUUCUUUUU). The end of the leader sequence (3' CUAAAA, which precedes gs1) could also be used for gene2 expression, but this sequence was considerably less efficient. Increasing the distance between ge1 and gs2 (up to 200 nt) led to the progressive loss of gene2 expression, in which half of gene2 expression was lost for each 70 nucleotides of intervening sequence. Beyond 200 nt, gene2 expression was lost more slowly. Our results suggest that there may be two populations of RdRp that scan at gene junctions, which can be distinguished by the efficiency with which they can scan the genome template for gs.
authors.affiliation: Department of Microbiology and Molecular Medicine, University of Geneva School of Medicine, C.M.U., 1211 Geneva, Switzerland.
authors.forename: Philippe
authors.initials: P
authors.lastname: Plattet
authors.forename: Laura
authors.initials: L
authors.lastname: Strahle
authors.forename: Philippe
authors.initials: P
authors.lastname: le Mercier
authors.forename: Stéphane
authors.initials: S
authors.lastname: Hausmann
authors.forename: Dominique
authors.initials: D
authors.lastname: Garcin
authors.forename: Daniel
authors.initials: D
authors.lastname: Kolakofsky
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D017124:Conserved Sequence; D006224:Cricetinae; D021901:DNA, Intergenic / Q000235:genetics*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D017930:Genes, Reporter / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000235:genetics; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D012367:RNA, Viral / Q000096:biosynthesis* / Q000235:genetics; D029082:Sendai virus / Q000201:enzymology*; D014158:Transcription, Genetic; D000097573:Red Fluorescent Protein
chemical_list: D021901:DNA, Intergenic; D012321:DNA-Directed RNA Polymerases; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D012333:RNA, Messenger; D012367:RNA, Viral; D000097573:Red Fluorescent Protein; C485184:enhanced green fluorescent protein