title: [Probable involvement of 3'-terminal segment of 18S rRNA in translation initiation of uncapped mRNAs in plants].
abstract: A possibility of involvement of 3'-terminal 18S rRNA segment in the cap-independent initiation of translation on plant ribosomes was studied. It was shown that 3-terminal segment (nucleotides 1777-1811) of 18S rRNA including the last hairpin 45 is accessible for complementary interactions in 40S ribosomal subunits. Oligonucleotides complementary to this segment of rRNA when added to wheat germ cell-free protein synthesizing system were found to specifically inhibit translation of uncapped reporter mRNA coding for beta-glucuronidase, which bears in the 5'-untranslated region (UTR) a leader sequence of potato virus Y (PVY) genomic RNA possessing fragments complementary to the region 1777-1811. It was shown that a sequence corresponding to nucleotides 291-316 of PVY, which is complementary to a major portion of the 3-terminal 18S rRNA segment 1777-1808, when placed into 5'-UTR, is able to enhance translational efficiency of the reporter mRNAs. The results obtained suggest that complementary interactions between mRNA 5'-UTR and 18S rRNA 3'-terminal segment can take place in the course of cap-independent translation initiation.
authors.forename: A V
authors.initials: AV
authors.lastname: Zhigaĭlov
authors.forename: E S
authors.initials: ES
authors.lastname: Babaĭlova
authors.forename: N S
authors.initials: NS
authors.lastname: Polimbetov
authors.forename: D M
authors.initials: DM
authors.lastname: Graĭfer
authors.forename: G G
authors.initials: GG
authors.lastname: Karpova
authors.forename: B K
authors.initials: BK
authors.lastname: Iskakov
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D020121:5' Untranslated Regions / Q000235:genetics; D001483:Base Sequence; D005966:Glucuronidase / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000737:chemistry / Q000235:genetics; D010442:Peptide Chain Initiation, Translational / Q000235:genetics*; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D012337:RNA, Ribosomal, 18S / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000737:chemistry / Q000235:genetics; D012639:Seeds / Q000235:genetics / Q000378:metabolism; D014908:Triticum / Q000235:genetics / Q000378:metabolism*
chemical_list: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D009841:Oligonucleotides; D012333:RNA, Messenger; D012337:RNA, Ribosomal, 18S; D005966:Glucuronidase