title: Leader sequence of a plant ribosomal protein gene with complementarity to the 18S rRNA triggers in vitro cap-independent translation.
abstract: Cap-independent translation (CIT) occurs at the leader sequences of uncapped plant viral RNAs, but also at a number of normally capped cellular mRNAs and has been correlated with sequence complementarity to 18S rRNA. The ribosomal protein S18 (RPS18) is a component of the small ribosomal subunit and is encoded by three gene copies (A, B, and C) in the Arabidopsis thaliana genome. The RPS18C mRNA was most abundant and contained a short 5' untranslated region of 84 bp that is complementary to a novel putative interaction site at the 3' end of the 18S rRNA. The RPS18C leader mediated CIT as demonstrated by dicistronic constructs consisting of luciferase and chloramphenicol acetyl transferase reporter genes in an in vitro wheat germ extract system. CIT was rapidly inhibited upon addition of an oligonucleotide that competed for the 18S rRNA site complementary to the RPS18C leader and interfered with polysome assembly at the transcript.
authors.affiliation: Department Plant Systems Biology, Flanders Interuniversitary Institute for Biotechnology, Ghent University, Technologiepark 927, B-9052 Gent, Belgium.
authors.forename: Rudy
authors.initials: R
authors.lastname: Vanderhaeghen
authors.forename: Rebecca
authors.initials: R
authors.lastname: De Clercq
authors.forename: Mansour
authors.initials: M
authors.lastname: Karimi
authors.forename: Marc
authors.initials: M
authors.lastname: Van Montagu
authors.forename: Pierre
authors.initials: P
authors.lastname: Hilson
authors.forename: Mieke
authors.initials: M
authors.lastname: Van Lijsebettens
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D020121:5' Untranslated Regions / Q000235:genetics*; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics*; D001483:Base Sequence; D018628:Gene Dosage / Q000235:genetics; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D014176:Protein Biosynthesis; D012315:RNA Caps / Q000235:genetics*; D012337:RNA, Ribosomal, 18S / Q000235:genetics*; D012269:Ribosomal Proteins / Q000235:genetics*; D014908:Triticum / Q000235:genetics / Q000378:metabolism
chemical_list: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D029681:Arabidopsis Proteins; D012315:RNA Caps; D012337:RNA, Ribosomal, 18S; D012269:Ribosomal Proteins; C041184:ribosomal protein S18