Synthesis of an ochre suppressor tRNA gene and expression in mammalian cells
Laski, F.A.; Belagaje, R.; Hudziak, R.M.; Capecchi, M.R.; Norton, G.P.; Palese, P.; RajBhandary, U.L.; Sharp, P.A.
EMBO Journal 3(11): 2445-2452
1984
ISSN/ISBN: 0261-4189 PMID: 6096120 Document Number: 231907
We have used site-specific mutagenesis to change the anticodon of a Xenopus laevis tyrosine tRNA gene so that it would recognize ochre codons. This tRNA gene is expressed when amplified in monkey cells as part of a SV40 recombinant and efficiently suppresses termination at both the ochre codon separating the adenovirus 2 hexon gene from a 23-kd downstream gene and the ochre codon at the end of the NS1 gene of influenza virus A/Tex/1/68. Termination at an amber codon of a NS1 gene of another influenza virus strain was not suppressed by the (Su+) ochre gene suggesting that in mammalian cells amber codons are not recognized by ochre suppressor tRNAs. Finally, microinjection into mammalian cells of both (Su+) ochre tRNA genes and selectible genes containing ochre nonsense mutations gives rise to colonies under selective conditions. We conclude that it should be possible to isolate a wide assortment of mammalian cell lines with ochre suppressor activity.