title: Ribosomal frameshifting in response to hypomodified tRNAs in Xenopus oocytes.
abstract: We used Xenopus oocytes as an intracellular system to study ribosomal frameshifting. Microinjection of oocytes with a construct encoding the naturally occurring UUU or AAC codon at the frameshift site demonstrated that the level of frameshifting was similar or lower than found normally in retroviral frameshifting in mammalian cells, suggesting that oocytes are a reliable system to study this event. Phenylalanine (Phe) or asparagine (Asn) tRNAs with and without the highly modified wyebutoxine (Y) or queuosine (Q) base, respectively, were microinjected to assess their ability to promote frameshifting. tRNAPhe+Y inhibited the level of frameshifting, while tRNAPhe-Y promoted frameshifting providing evidence that the hypomodified form does not act only to enhance frameshifting, but is an essential requirement. Both tRNAAsn+Q and tRNAAsn-Q were used indiscriminately in frameshifting, whether the frameshift site contained the wild-type AAC, or the mutant AAU codon, suggesting that Q base modification status does not influence this process.
authors.affiliation: Molecular Biology of Selenium Section, Laboratory of Cancer Prevention, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 9000 Rockville Pike, Building 37, Room 6032, Bethesda, MD 20892, USA. carlsonb@mail.nih.gov
authors.forename: Bradley A
authors.initials: BA
authors.lastname: Carlson
authors.forename: Byeong Jae
authors.initials: BJ
authors.lastname: Lee
authors.forename: Dolph L
authors.initials: DL
authors.lastname: Hatfield
mesh_terms: D000818:Animals; D001483:Base Sequence; D005260:Female; D018965:Frameshifting, Ribosomal; D006147:Guanine / Q000031:analogs & derivatives / Q000737:chemistry; D008845:Microinjections; D008969:Molecular Sequence Data; D009704:Nucleoside Q / Q000737:chemistry; D009865:Oocytes; D012348:RNA, Transfer, Asn / Q000737:chemistry / Q000235:genetics*; D012360:RNA, Transfer, Phe / Q000737:chemistry / Q000235:genetics*; D011817:Rabbits; D014981:Xenopus
chemical_list: D012348:RNA, Transfer, Asn; D012360:RNA, Transfer, Phe; C012099:wye; D009704:Nucleoside Q; D006147:Guanine