title: A novel interaction of Cap-binding protein complexes eukaryotic initiation factor (eIF) 4F and eIF(iso)4F with a region in the 3'-untranslated region of satellite tobacco necrosis virus.
abstract: Satellite tobacco necrosis virus (STNV) RNA is naturally uncapped at its 5' end and lacks polyadenylation at its 3' end. Despite lacking these two hallmarks of eukaryotic mRNAs, STNV-1 RNA is translated very efficiently. A approximately 130-nucleotide translational enhancer (TED), located 3' to the termination codon, is necessary for efficient cap-independent translation of STNV-1 RNA. The STNV-1 TED RNA fragment binds to the eukaryotic cap-binding complexes, initiation factor (eIF) 4F and eIF(iso)4F, as measured by nitrocellulose binding and fluorescence titration. STNV-1 TED is a potent inhibitor of in vitro translation when added in trans. This inhibition is reversed by the addition of eIF4F or eIF(iso)4F, and the subunits of eIF4F and eIF(iso)4F cross-link to STNV-1 TED, providing additional evidence that these factors interact directly with STNV-1 TED. Deletion mutagenesis of the STNV-1 TED indicates that a minimal region of approximately 100 nucleotides is necessary to promote cap-independent translation primarily through interaction with the cap binding subunits (eIF4E or eIF(iso)4E) of eIF4F or eIF(iso)4F.
authors.affiliation: Department of Chemistry and Biochemistry and the Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712, USA.
authors.forename: Brandy M
authors.initials: BM
authors.lastname: Gazo
authors.forename: Patricia
authors.initials: P
authors.lastname: Murphy
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Gatchel
authors.forename: Karen S
authors.initials: KS
authors.lastname: Browning
mesh_terms: D020413:3' Untranslated Regions / Q000502:physiology; D001483:Base Sequence; D039562:Eukaryotic Initiation Factor-4F / Q000378:metabolism*; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009690:Nucleic Acid Conformation; D011233:Precipitin Tests; D014176:Protein Biosynthesis; D012367:RNA, Viral / Q000235:genetics; D012270:Ribosomes / Q000502:physiology; D025641:Tobacco necrosis satellite virus / Q000235:genetics*; D020798:Two-Hybrid System Techniques; D014466:Ultraviolet Rays
chemical_list: D020413:3' Untranslated Regions; D039562:Eukaryotic Initiation Factor-4F; D012367:RNA, Viral