The antisuppressor strain sin1 of Schizosaccharomyces pombe lacks the modification isopentenyladenosine in transfer RNA

Janner, F.; Vögeli, Gabriel; Fluri, R.

doi:10.1016/0022-2836(80)90305-8

Cited by 51 publications

(31 citation statements)

References 26 publications

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“…Critical to this point would be undermodification of the hypermodified base position (1 base 3' of the anticodon). The hypermodification of this base has been implicated as critical to codon-anticodon interaction (4,12) and its undermodification results in an antisuppressor phenotype (20,29). However, all of the functional mutants showed the same level of suppression as the AIVS mutant, which contained the appropriate modification of this position (Fig.…”

Section: Resultsmentioning

confidence: 95%

Effect of intron mutations on processing and function of Saccharomyces cerevisiae SUP53 tRNA in vitro and in vivo.

Strobel¹,

Abelson²

1986

Mol. Cell. Biol.

102

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The Saccharomyces cerevisiae leucine-inserting amber suppressor tRNA gene SUP53 (a tRNA Le allele) was used to investigate the relationship between precursor tRNA structure and mature tRNA function. This gene encodes a pre-tRNA which contains a 32-base intron. The mature tRNASuPS3 contains a 5-methylcytosine modification of the anticodon wobble base. Mutations were made in the SUP53 intron. These mutant genes were transcribed in an S. cerevisiae nuclear extract preparation. In this extract, primary tRNA gene transcripts are end-processed and base modified after addition of cofactors. The base modifications made in vitro were examined, and the mutant pre-tRNAs were analyzed for their ability to serve as substrates for partially purified S. cerevisiae tRNA endonuclease and ligase. Finally, the suppressor function of these mutant tRNA genes was assayed after their integration into the S. cerevisiae genome. Mutant analysis showed that the totally intact precursor tRNA, rather than any specific sequence or structure of the intron, was necessary for efficient nonsense suppression by tRNASuPS3. Less efficient suppressor activity correlated with the absence of the 5-methylcytosine modification. Most of the intron-altered precursor tRNAs were successfully spliced in vitro, indicating that modifications are not critical for recognition by the tRNA endonuclease and ligase.Intervening sequences (IVS), or introns, have been found in the genes which encode the major classes of eucaryotic RNA, both nuclear and organellar. Recently, the mechanisms by which introns are removed from the primary RNA transcript have been the focus of intense investigation (reviewed in references 7, 14, and 51). However, relatively few experiments have elucidated a biological function for an IVS separate from the role of intron sequence or structure in the splicing process.Saccharomyces cerevisiae affords an ideal system for investigating intron function. A number of yeast nuclear mRNA and tRNA genes containing introns have been cloned. These genes can be mutated in vitro and the mutant phenotype assayed by introducing the mutated genes into yeast cells by chromosomal integration. Using these methods, Ng et al. (40) showed that precise removal of the S. cerevisiae actin gene intron did not affect the production of actin mRNA or actin protein in vivo. Cells containing only the intron-deleted actin gene exhibit a normal growth rate and normal meiotic products upon sporulation.In contrast, Johnson and Abelson (22) found that precise removal of the intron from an S. cerevisiae suppressor tRNA gene has profound effects on the phenotype of the mature suppressor tRNA product. Comparing strains containing the tyrosine-inserting ocher suppressor tRNASUP6 and its introndeleted counterpart SUP6A32, they found that SUP6A32 was inefficient in suppressing ocher nonsense mutations.When in vivo-labeled tRNATYr from the two strains was examined, SUP6-specific RNA from the deletion strain its total structure or some specific feature of the IVS itself, is recognized a...

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Section: Resultsmentioning

confidence: 95%

Effect of intron mutations on processing and function of Saccharomyces cerevisiae SUP53 tRNA in vitro and in vivo.

Strobel¹,

Abelson²

1986

Mol. Cell. Biol.

102

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“…+ , formerly known as sin1 + , derived from a genetic screen after NaNO2-induced mutagenesis (Thuriaux et al 1976), exhibit loss of codon-specific tRNA-mediated suppression (TMS) by sup3-e (and sup9-e), which encodes a serine-inserting tRNA Ser UCA Rafalski et al 1979;Egel et al 1980;Janner et al 1980). The multiple previously described sin1 mutants were mapped genetically but were not sequenced, and the precise mutations remain unknown (Thuriaux et al 1976;Kohli et al 1989).…”

Section: Mutants In Tit1mentioning

confidence: 99%

“…1C,D). The presence of at least two i 6 A-containing bands that migrated with the tRNAs suggests that substrates other than just the suppressor-tRNA Ser UCA , which is a minor tRNA Ser derived from the tRNA Ser UGA gene (Rafalski et al 1979;Janner et al 1980), are modified by Tit1p. Western blotting showed that Tit1p-T12A was expressed at a level comparable to Tit1p As reported (Keith et al 1971;Juhling et al 2009); N 6 of A37 appears unmodified based on in vitro modification by Tit1p.…”

Section: Mutants In Tit1mentioning

confidence: 99%

Plasticity and diversity of tRNA anticodon determinants of substrate recognition by eukaryotic A37 isopentenyltransferases

Lamichhane¹,

Blewett²,

Maraia³

2011

RNA

139

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The N 6 -(isopentenyl)adenosine (i 6 A) modification of some tRNAs at position A37 is found in all kingdoms and facilitates codonspecific mRNA decoding, but occurs in different subsets of tRNAs in different species. Here we examine yeasts' tRNA isopentenyltransferases (i.e., dimethylallyltransferase, DMATase, members of the D 2 -isopentenylpyrophosphate transferase, IPPT superfamily) encoded by tit1 + in Schizosaccharomyces pombe and MOD5 in Saccharomyces cerevisiae, whose homologs are Escherichia coli miaA, the human tumor suppressor TRIT1, and the Caenorhabditis elegans life-span gene product GRO-1. A major determinant of miaA activity is known to be the single-stranded tRNA sequence, A36A37A38, in a stem-loop. tRNA Trp CCA from either yeast is a Tit1p substrate, but neither is a Mod5p substrate despite the presence of A36A37A38. We show that Tit1p accommodates a broader range of substrates than Mod5p. tRNA Trp CCA is distinct from Mod5p substrates, which we sort into two classes based on the presence of G at position 34 and other elements. A single substitution of C34 to G converts tRNA Trp CCA to a Mod5p substrate in vitro and in vivo, consistent with amino acid contacts to G34 in existing Mod5p-tRNA Cys GCA crystal structures. Mutation of Mod5p in its G34 recognition loop region debilitates it differentially for its G34 (class I) substrates. Multiple alignments reveal that the G34 recognition loop sequence of Mod5p differs significantly from Tit1p, which more resembles human TRIT1 and other DMATases. We show that TRIT1 can also modify tRNA Trp CCA consistent with broad recognition similar to Tit1p. This study illustrates previously unappreciated molecular plasticity and biological diversity of the tRNA-isopentenyltransferase system of eukaryotes.

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“…One of these possibilities became a reality for antisuppressor mutation sin1 efficient against serine-inserting UGA suppressor (mutant tRNA Ser in Schizosaccharomyces pombe). Mutation sin1 caused a defect in tRNA modification and so the absence of isopentenyladenosine adjacent to 3' side of the anticodon (Janner et al, 1980). S. cerevisiae antisuppressors: asu9, efficient with both sup35 and sup45 mutation and ASU10, specific only for sup35, but not for sup45 had been isolated by .…”

Section: Antisuppressionmentioning

confidence: 99%

Eukaryotic release factors (eRFs) history

Инге-Вечтомов

Zhouravleva

Maury

2003

Biology of the Cell

113

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In the present review, we describe the history of the identification of the eukaryotic translation termination factors eRF1 and eRF3. As in the case of several proteins involved in general and essential processes in all cells (e.g., DNA replication, gene expression regulation...) the strategies and methodologies used to identify these release factors were first established in prokaryotes. The genetic investigations in Saccharomyces cerevisiae have made a major contribution in the field. A large amount of data have been produced, from which it was concluded that the SUP45 and SUP35 genes were controlling translation termination but were also involved in other functions important for the cell organization and the cell cycle accomplishment. This does not seem to be restricted to yeast but is also probably the case in eukaryotes in general. The biochemical studies of the proteins encoded by the higher eukaryote homologs of SUP45 and SUP35 were efficient and permitted the identification of eRF1 as being the key protein in the termination process, eRF3 having a stimulating role. Around 25 years were needed after the identification of sup45 and sup35 mutants for the characterization of their gene products as eRF1 and eRF3, respectively. It also has to be pointed out that if the results came first from bacteria, the identification of RF3 and eRF3 was made practically at the same time. Moreover, eRF1 was the first crystal structure obtained for a class-1 release factor, the bacterial RF2 structure came later. The goal is now to understand at the molecular level the roles of both eRF1 and eRF3 in addition to their translation termination functions.

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The antisuppressor strain sin1 of Schizosaccharomyces pombe lacks the modification isopentenyladenosine in transfer RNA

Cited by 51 publications

References 26 publications

Effect of intron mutations on processing and function of Saccharomyces cerevisiae SUP53 tRNA in vitro and in vivo.

Effect of intron mutations on processing and function of Saccharomyces cerevisiae SUP53 tRNA in vitro and in vivo.

Plasticity and diversity of tRNA anticodon determinants of substrate recognition by eukaryotic A37 isopentenyltransferases

Eukaryotic release factors (eRFs) history

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