1
|
Incorporation of non-canonical amino acids into proteins in yeast. Fungal Genet Biol 2016; 89:137-156. [DOI: 10.1016/j.fgb.2016.02.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 02/01/2016] [Accepted: 02/03/2016] [Indexed: 12/22/2022]
|
2
|
Petrova A, Kiktev D, Askinazi O, Chabelskaya S, Moskalenko S, Zemlyanko O, Zhouravleva G. The translation termination factor eRF1 (Sup45p) of Saccharomyces cerevisiae is required for pseudohyphal growth and invasion. FEMS Yeast Res 2015; 15:fov033. [PMID: 26054854 DOI: 10.1093/femsyr/fov033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/26/2015] [Indexed: 01/16/2023] Open
Abstract
Mutations in the essential genes SUP45 and SUP35, encoding yeast translation termination factors eRF1 and eRF3, respectively, lead to a wide range of phenotypes and affect various cell processes. In this work, we show that nonsense and missense mutations in the SUP45, but not the SUP35, gene abolish diploid pseudohyphal and haploid invasive growth. Missense mutations that change phosphorylation sites of Sup45 protein do not affect the ability of yeast strains to form pseudohyphae. Deletion of the C-terminal part of eRF1 did not lead to impairment of filamentation. We show a correlation between the filamentation defect and the budding pattern in sup45 strains. Inhibition of translation with specific antibiotics causes a significant reduction in pseudohyphal growth in the wild-type strain, suggesting a strong correlation between translation and the ability for filamentous growth. Partial restoration of pseudohyphal growth by addition of exogenous cAMP assumes that sup45 mutants are defective in the cAMP-dependent pathway that control filament formation.
Collapse
Affiliation(s)
- Alexandra Petrova
- Department of Genetics and Biotechnology, St Petersburg State University and St Petersburg Branch Vavilov Institute of General Genetics, Russian Academy of Science, Universitetskaya emb. 7/9, 199034, St Petersburg, Russia
| | - Denis Kiktev
- Department of Genetics and Biotechnology, St Petersburg State University and St Petersburg Branch Vavilov Institute of General Genetics, Russian Academy of Science, Universitetskaya emb. 7/9, 199034, St Petersburg, Russia
| | - Olga Askinazi
- Department of Genetics and Biotechnology, St Petersburg State University and St Petersburg Branch Vavilov Institute of General Genetics, Russian Academy of Science, Universitetskaya emb. 7/9, 199034, St Petersburg, Russia
| | - Svetlana Chabelskaya
- Department of Genetics and Biotechnology, St Petersburg State University and St Petersburg Branch Vavilov Institute of General Genetics, Russian Academy of Science, Universitetskaya emb. 7/9, 199034, St Petersburg, Russia
| | - Svetlana Moskalenko
- Department of Genetics and Biotechnology, St Petersburg State University and St Petersburg Branch Vavilov Institute of General Genetics, Russian Academy of Science, Universitetskaya emb. 7/9, 199034, St Petersburg, Russia
| | - Olga Zemlyanko
- Department of Genetics and Biotechnology, St Petersburg State University and St Petersburg Branch Vavilov Institute of General Genetics, Russian Academy of Science, Universitetskaya emb. 7/9, 199034, St Petersburg, Russia
| | - Galina Zhouravleva
- Department of Genetics and Biotechnology, St Petersburg State University and St Petersburg Branch Vavilov Institute of General Genetics, Russian Academy of Science, Universitetskaya emb. 7/9, 199034, St Petersburg, Russia
| |
Collapse
|
3
|
Murina OA, Moskalenko SE, Zhouravleva GA. Overexpression of genes encoding tRNATyr and tRNAGln increases the viability of Saccharomyces cerevisiae strains with nonsense mutations in the SUP45 gene. Mol Biol 2010. [DOI: 10.1134/s0026893310020123] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
4
|
Zhouravleva GA, Zemlyanko OM, Le Goff C, Petrova AV, Philippe M, Inge-Vechtomov SG. Conservation of the MC domains in eukaryotic release factor eRF3. RUSS J GENET+ 2007. [DOI: 10.1134/s102279540701005x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
5
|
Zhouravleva GA, Moskalenko SE, Chabelskaya SV, Philippe M, Inge-Vechtomov SG. Increased tRNA level in yeast cells with mutant translation termination factors eRF1 and eRF3. Mol Biol 2006. [DOI: 10.1134/s0026893306040170] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
6
|
Ono BI, Yoshida R, Kamiya K, Sugimoto T. Suppression of termination mutations caused by defects of the NMD machinery in Saccharomyces cerevisiae. Genes Genet Syst 2006; 80:311-6. [PMID: 16394582 DOI: 10.1266/ggs.80.311] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Among a large collection of nonsense (termination) suppressors of Saccharomyces cerevisiae, a few remained obscure for their molecular nature. Of those, a group of weak and recessive suppressors, sup111, sup112 and sup113, is of particular interest because of their dependency on [PSI+], a yeast prion. From the facts that these suppressors map at positions quite similar to the UPF2, UPF3 and UPF1 genes, respectively, and that some mutations in the UPF genes confer termination suppressor activity, we suspected that sup111, sup112 and sup113 would very well be mutant alleles of the UPF genes. We tested our speculation and found that sup113, sup111 and sup112 were in fact complemented with the wild-type alleles of UPF1, UPF2 and UPF3, respectively. We further obtained evidence that the UPF1, UPF2 and UPF3 loci of the strains carrying sup113, sup111 and sup112, respectively, had point mutations. From these results, we conclude that sup111, sup112 and sup113 are mutant alleles of UPF2, UPF3 and UPF1, respectively, and thus attribute suppressor activity of these mutations to defects in the NMD (nonsense-mediated mRNA decay) machinery.
Collapse
Affiliation(s)
- Bun-Ichiro Ono
- Department of Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga, Japan.
| | | | | | | |
Collapse
|
7
|
Bradley ME, Bagriantsev S, Vishveshwara N, Liebman SW. Guanidine reduces stop codon read-through caused by missense mutations in SUP35 or SUP45. Yeast 2003; 20:625-32. [PMID: 12734800 DOI: 10.1002/yea.985] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sup35 and Sup45 are essential protein components of the Saccharomyces cerevisiae translation termination factor. Yeast cells harbouring the [PSI(+)] prion form of Sup35 have impaired stop codon recognition (nonsense suppression). It has long been known that the [PSI(+)] prion is not stably transmitted to daughter cells when yeast are grown in the presence of mM concentrations of guanidine hydrochloride (GuHCl). In this paper, Mendelian suppressor mutations whose phenotypes are likewise hidden during growth in the presence of millimolar GuHCl are described. Such GuHCl-remedial Mendelian suppressors were selected under conditions where [PSI(+)] appearance was limiting, and were caused by missense mutations in SUP35 or SUP45. Clearly, anti-suppression caused by growth in the presence of GuHCl is not sufficient to distinguish missense mutations in SUP35 or SUP45, from [PSI(+)]. However, the Mendelian and prion suppressors can be distinguished by subsequent growth in the absence of GuHCl, where only the nonsense suppression caused by the [PSI(+)] prion remains cured. Recent reports indicate that GuHCl blocks the inheritance of [PSI(+)] by directly inhibiting the activity of the protein remodelling factor Hsp104, which is required for the transmission of [PSI(+)] from mother to daughter cells. However, the nonsense suppressor activity caused by the GuHCl-remedial sup35 or sup45 suppressors does not require Hsp104. Thus, GuHCl must anti-suppress the sup35 and sup45 mutations via an in vivo target distinct from Hsp104.
Collapse
Affiliation(s)
- Michael E Bradley
- Laboratory for Molecular Biology, Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | | | | | | |
Collapse
|
8
|
Le Goff C, Zemlyanko O, Moskalenko S, Berkova N, Inge-Vechtomov S, Philippe M, Zhouravleva G. Mouse GSPT2, but not GSPT1, can substitute for yeast eRF3 in vivo. Genes Cells 2002; 7:1043-57. [PMID: 12354098 DOI: 10.1046/j.1365-2443.2002.00585.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The termination of protein synthesis in eukaryotes involves at least two polypeptide release factors (eRFs), eRF1 and eRF3. In mammals two genes encoding eRF3 structural homologues were identified and named GSPT1 and GSPT2. RESULTS In the present study, we demonstrate that mouse mGSPT2 but not mGSPT1 could functionally substitute the essential yeast gene SUP35. However, we show that the complementation property of mGSPT1 protein is modified when NH2-tagged by GST. Since mGSPT1 and mGSPT2 differ mainly in their N-terminal regions, we developed a series of N-terminal deleted constructs and tested them for complementation in yeast. We found that at least amino acids spanning 84-120 of mGSPT1 prevent the complementation of sup35 mutation. The fact that chimeras between mGSPT1, mGSPT2 and yeast Sup35 complement the disruption of the SUP35 gene indicates that the N-terminal region of mGSPT1 is not sufficient by itself to prevent complementation. Complementation of the mutant with a double disruption of SUP35 and SUP45 genes is obtained when mGSPT2 and human eRF1 are co-expressed but not by co-expression of mGSPT1 and human eRF1. CONCLUSIONS Our results strongly suggest that the two proteins (mGSPT1 and mGSPT2) are different. We hypothesize that the full length mGSPT1 does not have the properties expected for eRF3.
Collapse
Affiliation(s)
- Catherine Le Goff
- Université de Rennes 1, CNRS UMR 6061, IFR 97, 2 av Pr Léon Bernard 35043 Rennes Cedex, France
| | | | | | | | | | | | | |
Collapse
|
9
|
Velichutina IV, Hong JY, Mesecar AD, Chernoff YO, Liebman SW. Genetic interaction between yeast Saccharomyces cerevisiae release factors and the decoding region of 18 S rRNA. J Mol Biol 2001; 305:715-27. [PMID: 11162087 DOI: 10.1006/jmbi.2000.4329] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Functional and structural similarities between tRNA and eukaryotic class 1 release factors (eRF1) described previously, provide evidence for the molecular mimicry concept. This concept is supported here by the demonstration of a genetic interaction between eRF1 and the decoding region of the ribosomal RNA, the site of tRNA-mRNA interaction. We show that the conditional lethality caused by a mutation in domain 1 of yeast eRF1 (P86A), that mimics the tRNA anticodon stem-loop, is rescued by compensatory mutations A1491G (rdn15) and U1495C (hyg1) in helix 44 of the decoding region and by U912C (rdn4) and G886A (rdn8) mutations in helix 27 of the 18 S rRNA. The rdn15 mutation creates a C1409-G1491 base-pair in yeast rRNA that is analogous to that in prokaryotic rRNA known to be important for high-affinity paromomycin binding to the ribosome. Indeed, rdn15 makes yeast cells extremely sensitive to paromomycin, indicating that the natural high resistance of the yeast ribosome to paromomycin is, in large part, due to the absence of the 1409-1491 base-pair. The rdn15 and hyg1 mutations also partially compensate for inactivation of the eukaryotic release factor 3 (eRF3) resulting from the formation of the [PSI+] prion, a self-reproducible termination-deficient conformation of eRF3. However, rdn15, but not hyg1, rescues the conditional cell lethality caused by a GTPase domain mutation (R419G) in eRF3. Other antisuppressor rRNA mutations, rdn2(G517A), rdn1T(C1054T) and rdn12A(C526A), strongly inhibit [PSI+]-mediated stop codon read-through but do not cure cells of the [PSI+] prion. Interestingly, cells bearing hyg1 seem to enable [PSI+] strains to accumulate larger Sup35p aggregates upon Sup35p overproduction, suggesting a lower toxicity of overproduced Sup35p when the termination defect, caused by [PSI+], is partly relieved.
Collapse
MESH Headings
- Anti-Bacterial Agents/metabolism
- Anti-Bacterial Agents/pharmacology
- Anticodon/chemistry
- Anticodon/genetics
- Base Pairing
- Base Sequence
- Codon, Terminator/genetics
- Drug Resistance, Microbial
- Frameshift Mutation/genetics
- Fungal Proteins/chemistry
- Fungal Proteins/genetics
- Fungal Proteins/metabolism
- Genes, Fungal/genetics
- Genes, Lethal/genetics
- Paromomycin/metabolism
- Paromomycin/pharmacology
- Peptide Termination Factors/biosynthesis
- Peptide Termination Factors/chemistry
- Peptide Termination Factors/genetics
- Peptide Termination Factors/metabolism
- Protein Biosynthesis/drug effects
- RNA, Ribosomal, 18S/chemistry
- RNA, Ribosomal, 18S/genetics
- RNA, Ribosomal, 18S/metabolism
- Ribosomes/metabolism
- Saccharomyces cerevisiae/cytology
- Saccharomyces cerevisiae/drug effects
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
- Suppression, Genetic/genetics
Collapse
Affiliation(s)
- I V Velichutina
- Laboratory for Molecular Biology, Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | | | | | | | | |
Collapse
|
10
|
Culbertson MR. RNA surveillance. Unforeseen consequences for gene expression, inherited genetic disorders and cancer. Trends Genet 1999; 15:74-80. [PMID: 10098411 DOI: 10.1016/s0168-9525(98)01658-8] [Citation(s) in RCA: 310] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Messenger RNAs are monitored for errors that arise during gene expression by a mechanism called RNA surveillance, with the result that most mRNAs that cannot be translated along their full length are rapidly degraded. This ensures that truncated proteins are seldom made, reducing the accumulation of rogue proteins that might be deleterious. The pathway leading to accelerated mRNA decay is referred to as nonsense-mediated mRNA decay (NMD). The proteins that catalyze steps in NMD in yeast serve two roles, one to monitor errors in gene expression and the other to control the abundance of endogenous wild-type mRNAs as part of the normal repertoire of gene expression. The NMD pathway has a direct impact on hundreds of genetic disorders in the human population, where about a quarter of all known mutations are predicted to trigger NMD.
Collapse
Affiliation(s)
- M R Culbertson
- Laboratory of Genetics, R.M. Bock Laboratories, University of Wisconsin, Madison 53706, USA.
| |
Collapse
|
11
|
Urbero B, Eurwilaichitr L, Stansfield I, Tassan JP, Le Goff X, Kress M, Tuite MF. Expression of the release factor eRF1 (Sup45p) gene of higher eukaryotes in yeast and mammalian tissues. Biochimie 1997; 79:27-36. [PMID: 9195043 DOI: 10.1016/s0300-9084(97)87622-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Polypeptide chain termination in eukaryotic cells is mediated in part by the release factor eRF1 (Sup45p). We have isolated and characterised cDNAs encoding this translation factor from Syrian hamster (Mesocricetus auratus) and human (Homo sapiens) Daudi cells. Comparison of the deduced amino acid sequence of these new eRF1 (Sup45p) sequences with those published for Saccharomyces cerevisiae, Arabidopsis thaliana, Xenopus laevis and human indicates a high degree of amino acid identity across a broad evolutionary range of species. Both the 5' and 3' UTRs of the mammalian eRF1 (Sup45p)-encoding cDNAs show an unusually high degree of conservation for non-coding regions. In addition, the presence of two different lengths of 3' UTR sequences in the mammalian eRF1 (Sup45p) cDNAs indicated that alternative polyadenylation sites might be used in vivo. Northern blot analysis demonstrated that eRF1 (Sup45p) transcripts of differing length, consistent with the use of alternative polyadenylation sites, were detectable in a wide range of mammalian tissues. The Xenopus, human and Syrian hamster eRF1 (Sup45p) cDNAs were shown to support the viability of a strain of S cerevisiae carrying an otherwise lethal sup45::HIS3 gene disruption indicating evolutionary conservation of function. However, the yeast strains expressing the heterogenous eRF1 (Sup45p) showed a defect in translation termination as defined by an enhancement of nonsense suppressor tRNA activity in vivo. Western blot analysis confirmed that Xenopus eRF1 (Sup45p) was primarily ribosome-associated when expressed in yeast indicating that the ribosome-binding domain of eRF1 (Sup45p) is also conserved.
Collapse
Affiliation(s)
- B Urbero
- Genetique Moleculaire et Integration des Fonctions Cellulaire, CNRS UPR9044, IRC, Villejuif, France
| | | | | | | | | | | | | |
Collapse
|
12
|
Abstract
Protein synthesis in both eukaryotic and prokaryotic cells is a complex process requiring a large number of macromolecules: initiation factors, elongation factors, termination factors, ribosomes, mRNA, amino-acylsynthetases and tRNAs. This review focuses on our current knowledge of protein synthesis in higher plants.
Collapse
Affiliation(s)
- K S Browning
- Department of Chemistry and Biochemistry, University of Texas at Austin 78712, USA
| |
Collapse
|
13
|
Stansfield I, Eurwilaichitr L, Tuite MF. Depletion in the levels of the release factor eRF1 causes a reduction in the efficiency of translation termination in yeast. Mol Microbiol 1996; 20:1135-43. [PMID: 8809766 DOI: 10.1111/j.1365-2958.1996.tb02634.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In Saccharomyces cerevisiae, translation termination is mediated by a complex of two proteins, eRF1 and eRF3, encoded by the SUP45 and SUP35 genes, respectively. Mutations in the SUP45 gene were selected which enhanced suppression by the weak ochre (UAA) suppressor tRNA(Ser) SUQ5. In each of four such allosuppressor alleles examined, an in-frame ochre (TAA) mutation was present in the SUP45 coding region; therefore each allele encoded both a truncated eRF1 protein and a full-length eRF1 polypeptide containing a serine missense substitution at the premature UAA codon. The full-length eRF1 generated by UAA read-through was present at sub-wild-type levels. In an suq5+ (i.e. non-suppressor) background none of the truncated eRF1 polypeptides were able to support cell viability, with the loss of only 27 amino acids from the C-terminus being lethal. The reduced eRF1 levels in these sup45 mutants did not lead to a proportional reduction in the levels of ribosome-bound eRF3, indicating that eRF3 can bind the ribosome independently of eRF1. A serine codon inserted in place of the premature stop codon at codon 46 in the sup45-22 allele did not generate an allosuppressor phenotype, thereby ruling out this "missense' mutation as the cause of the allosuppressor phenotype. These data indicate that the cellular levels of eRF1 are important for ensuring efficient translation termination in yeast.
Collapse
Affiliation(s)
- I Stansfield
- Research School of Biosciences, University of Kent, Canterbury, UK
| | | | | |
Collapse
|
14
|
Kinzy TG, Woolford JL. Increased expression of Saccharomyces cerevisiae translation elongation factor 1 alpha bypasses the lethality of a TEF5 null allele encoding elongation factor 1 beta. Genetics 1995; 141:481-9. [PMID: 8647386 PMCID: PMC1206749 DOI: 10.1093/genetics/141.2.481] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Translation elongation factor 1beta (EF-1beta) catalyzes the exchange of bound GDP for GTP on EF-1alpha. The lethality of a null allele of the TEF5 gene encoding EF-1beta in Saccharomyces cerevisiae was suppressed by extra copies of the TEF2 gene encoding EF-1alpha. The strains with tef5::TRP1 suppressed by extra copies of TEF were slow growing, cold sensitive, hypersensitive to inhibitors of translation elongation and showed increased phenotypic suppression of +1 frameshift and UAG nonsense mutations. Nine dominant mutant alleles of TEF2 that cause increased suppression of frameshift mutations also suppressed the lethality of tef5::TRP1. Most of the strains in which tef5::TRP1 is suppressed by dominant mutant alleles of TEF2 grew more slowly and were more antibiotic sensitive than strains with tef5::TRP1 is suppressed by wild-type TEF2. Two alleles, TEF2-4 and TEF2-10, interact with tef5::TRP1 to produce strains that showed doubling times similar to tef5::TRP1 strains containing extra copies of wild-type TEF2. These strains were less cold sensitive, drug sensitive and correspondingly less efficient suppressor of +1 frameshift mutations. These phenotypes indicate that translation and cell growth are highly sensitive to changes in EF-1alpha and EF-1beta activity.
Collapse
Affiliation(s)
- T G Kinzy
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | | |
Collapse
|
15
|
Frolova L, Le Goff X, Rasmussen HH, Cheperegin S, Drugeon G, Kress M, Arman I, Haenni AL, Celis JE, Philippe M. A highly conserved eukaryotic protein family possessing properties of polypeptide chain release factor. Nature 1994; 372:701-3. [PMID: 7990965 DOI: 10.1038/372701a0] [Citation(s) in RCA: 291] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The termination of protein synthesis in ribosomes is governed by termination (stop) codons in messenger RNAs and by polypeptide chain release factors (RFs). Although the primary structure of prokaryotic RFs and yeast mitochrondrial RF is established, that of the only known eukaryotic RF (eRF) remains obscure. Here we report the assignment of a family of tightly related proteins (designated eRF1) from lower and higher eukaryotes which are structurally and functionally similar to rabbit eRF. Two of these proteins, one from human and the other from Xenopus laevis, have been expressed in yeast and Escherichia coli, respectively, purified and shown to be active in the in vitro RF assay. The other protein of this family, sup45 (sup1) of Saccharomyces cerevisiae, is involved in omnipotent suppression during translation. The amino-acid sequence of the eRF1 family is highly conserved. We conclude that the eRF1 proteins are directly implicated in the termination of translation in eukaryotes.
Collapse
Affiliation(s)
- L Frolova
- Department of Molecular Biology, University of Aarhus, Denmark
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Vincent A, Newnam G, Liebman SW. The yeast translational allosuppressor, SAL6: a new member of the PP1-like phosphatase family with a long serine-rich N-terminal extension. Genetics 1994; 138:597-608. [PMID: 7851758 PMCID: PMC1206211 DOI: 10.1093/genetics/138.3.597] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The allosuppressor mutation, sal6-1, enhances the efficiency of all tested translational suppressors, including codon-specific tRNA suppressors as well as codon-nonspecific omnipotent suppressors. The SAL6 gene has now been cloned by complementation of the increased suppression efficiency and cold sensitivity caused by sal6-1 in the presence of the omnipotent suppressor sup45. Physical analysis maps SAL6 to chromosome XVI between TPK2 and spt14. The SAL6 gene encodes a very basic 549-amino acid protein whose C-terminal catalytic region of 265 residues is 63% identical to serine/threonine PP1 phosphatases, and 66% identical to yeast PPZ1 and PPZ2 phosphatases. The unusual 235 residue N-terminal extension found in SAL6, like those in the PPZ proteins, is serine-rich. The sal6-1 mutation is a frameshift at amino acid position 271 which destroys the presumed phosphatase catalytic domain of the protein. Disruptions of the entire SAL6 gene are viable, cause a slight growth defect on glycerol medium, and produce allosuppressor phenotypes in suppressor strain backgrounds. The role of the serine-rich N terminus is unclear, since sal6 phenotypes are fully complemented by a SAL6 allele that contains an in-frame deletion of most of this region. High copy number plasmids containing wild-type SAL6 cause antisuppressor phenotypes in suppressor strains. These results suggest that the accuracy of protein synthesis is affected by the levels of phosphorylation of the target(s) of SAL6.
Collapse
Affiliation(s)
- A Vincent
- Department of Biological Sciences, University of Illinois at Chicago 60680
| | | | | |
Collapse
|
17
|
Abstract
The study of translational termination in yeast has been approached largely through the identification of a range of mutations which either increase or decrease the efficiency of stop-codon recognition. Subsequent cloning of the genes encoding these factors has identified a number of proteins important for maintaining the fidelity of termination, including at least three ribosomal proteins (S5, S13, S28). Other non-ribosomal proteins have been identified by mutations which produce gross termination-accuracy defects, namely the SUP35 and SUP45 gene products which have closely-related higher eukaryote homologues (GST1-h and SUP45-h respectively) and which can complement the corresponding defective yeast proteins, implying that the yeast ribosome may be a good model for the termination apparatus existing in higher translation systems. While the yeast mitochondrial release factor has been cloned (Pel et al. 1992), the corresponding cytosolic RF has not yet been identified. It seems likely, however, that the identification of the gene encoding eRF could be achieved using a multicopy antisuppressor screen such as that employed to clone the E. coli prfA gene (Weiss et al. 1984). Identification of the yeast eRF and an investigation of its interaction with other components of the yeast translational machinery will no doubt further the definition of the translational termination process. While a large number of mutations have been isolated in which the efficiency of termination-codon recognition is impaired, it seems probable that a proportion of mutations within this class will comprise those where the accuracy of 'A' site codon-anticodon interaction is compromised: such defects would also have an effect on termination-codon suppression, allowing mis- or non-cognate tRNAs to bind stop-codons, causing nonsense suppression. The remainder of mutations affecting termination fidelity should represent mutations in genes coding for components of the termination apparatus, including the eRF: these mutations reduce the efficiency of termination, allowing nonsense suppression by low-efficiency natural suppressor tRNAs. Elucidation of the mechanism of termination in yeast will require discrimination between these two classes of mutations, thus allowing definition of termination-specific gene products.
Collapse
Affiliation(s)
- I Stansfield
- Research School of Biosciences, University of Kent, Canterbury, UK
| | | |
Collapse
|
18
|
Miosga T, Zimmermann FK. Sequence and function analysis of a 2.73 kb fragment of Saccharomyces cerevisiae chromosome II. Yeast 1993; 9:1273-7. [PMID: 8109177 DOI: 10.1002/yea.320091115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The nucleotide sequence of a fragment of 2728 base pairs of Saccharomyces cerevisiae chromosome II has been determined. The sequence contains two open reading frames, one of them being incomplete. Deletion mutants of YBR11.21 are viable. YBR11.20 is identical to the recessive omnipotent suppressor SUP45 (SUP1).
Collapse
Affiliation(s)
- T Miosga
- Institut für Mikrobiologie, TH Darmstadt, Germany
| | | |
Collapse
|
19
|
Stansfield I, Grant GM, Akhmaloka, Tuite MF. Ribosomal association of the yeast SAL4 (SUP45) gene product: implications for its role in translation fidelity and termination. Mol Microbiol 1992; 6:3469-78. [PMID: 1474892 DOI: 10.1111/j.1365-2958.1992.tb01782.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The SAL4 gene of the yeast Saccharomyces cerevisiae encodes a novel translation factor (Sal4p) involved in maintaining translational fidelity. Using a polyclonal antibody raised against a Sal4p-beta-galactosidase fusion protein, Sal4p was shown to be almost exclusively associated with the ribosomal fraction. Even when the ribosomes were treated with 0.8 M KCl, only low levels of Sal4p were detected in the post-ribosomal supernatant, suggesting a very strong affinity between Sal4p and the ribosome. Analysis of the distribution of Sal4p in the ribosomal population revealed that it was principally associated with 40S subunits, monosomes and polysomes. Incubation in high salt concentrations (0.8 M KCl) suggested that the affinity of Sal4p for the 40S subunit was lower than that for monosomes or polysomes. The Sal4p:ribosome association was only maintained when ribosomes were prepared in the presence of the translation elongation inhibitor cycloheximide; in uninhibited cells much lower levels of Sal4p were detectable in the 'run-off' polysomes. In view of these data, and given the stoichiometry of Sal4p to individual ribosomal proteins (estimated at less than 1:20), we suggest that Sal4p plays an ancillary role in translation termination.
Collapse
Affiliation(s)
- I Stansfield
- Biological Laboratory, University of Kent, Canterbury, UK
| | | | | | | |
Collapse
|
20
|
Chernoff YO, Inge-Vechtomov SG, Derkach IL, Ptyushkina MV, Tarunina OV, Dagkesamanskaya AR, Ter-Avanesyan MD. Dosage-dependent translational suppression in yeast Saccharomyces cerevisiae. Yeast 1992; 8:489-99. [PMID: 1523883 DOI: 10.1002/yea.320080702] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The overexpression of SUP35 (SUP2) wild-type gene, caused by increase of its copy number, induces an omnipotent suppression similar to the phenotype of mutants for this gene. The effect of extra-SUP35 was detected for moderate or even low copy number. Moreover, overdosage of the fragment including only the 5'-flanking region and N-terminal 100 bp of protein-coding sequence of SUP35 leads to allosuppression. Multi-SUP35 gene was also incompatible with extrachromosomal suppressor factor psi, presumably because of a high level of mistranslation. The suppressor effect caused by overdosage of another gene, SUP45 (SUP1), is much lower and can be detected only for one construction which is derived from high copy number plasmid. Suppression induced by extra-SUP35 and especially by extra-SUP45 is affected by the cell environment. A model predicting that the balance of gene products is a key for regulation of translational fidelity is discussed.
Collapse
Affiliation(s)
- Y O Chernoff
- Department of Genetics, Leningrad University, U.S.S.R
| | | | | | | | | | | | | |
Collapse
|
21
|
Chernoff YO, Ptyushkina MV, Samsonova MG, Sizonencko GI, Pavlov YI, Ter-Avanesyan MD, Inge-Vechtomov SG. Conservative system for dosage-dependent modulation of translational fidelity in eukaryotes. Biochimie 1992; 74:455-61. [PMID: 1637871 DOI: 10.1016/0300-9084(92)90086-t] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Variations in dosage of some genes can alter the level of translational fidelity. The Saccharomyces cerevisiae genes that act as dosage-dependent suppressors and/or modulators of suppression, are the following: some tRNA genes (for example, tRNA(Gln)) inducing readthrough by mispairing; genes coding for either translational elongation factor or other proteins taking part in translation; and some genes of unknown function. We suggest that the SUP35 protein is a factor which may play a major role in balance-dependent regulation of translational fidelity. Homologues of this genes have been identified in other yeast genera (Pichia), green algae (Chlamydomonas) and various animals including man. No homologies have been found in the polychaeta (Nereis) or in insects (Drosophila). Rates of evolution differ for two separate parts of the genes; the N-terminal part, which is important for ambiguous translation in Saccharomyces, is markedly variable in the organisms tested. However, the C-terminal part which is required for yeast viability has a common origin but a separate evolution from that of the EF-Tu protein family.
Collapse
Affiliation(s)
- Y O Chernoff
- Department of Genetics, Leningrad University, Moscow, Russia
| | | | | | | | | | | | | |
Collapse
|
22
|
Grenett HE, Bounelis P, Fuller GM. Identification of a human cDNA with high homology to yeast omnipotent suppressor 45. Gene X 1992; 110:239-43. [PMID: 1537561 DOI: 10.1016/0378-1119(92)90655-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Omnipotent suppression is a well-established phenomenon in yeast and bacteria in which nonsense mutations are misread. Wild-type (wt) suppressors are presumed to be involved in ensuring the fidelity of translation. We report a human homolog to wt yeast omnipotent suppressor 45 which shares 63% identity at the nucleotide level in the area of open reading frame (ORF) and 73% similarity at the amino acid (aa) level. The aa sequence of the human protein was deduced from a 2.3-kb cDNA (TB3-1) isolated from an adenocarcinoma T84 cell line cDNA library. The cDNA contains an ORF of 1284 bp which encodes a 47.8-kDa protein. Two transcripts for the clone were identified (2.6 and 4.0 kb) in a variety of human cell types. The strong structural similarity to yeast omnipotent suppressor 45, and its widespread expression suggest that this cDNA may play a role in the accurate recognition of nonsense codons in mammalian cells.
Collapse
Affiliation(s)
- H E Grenett
- Department of Cell Biology, University of Alabama, Birmingham 35294
| | | | | |
Collapse
|
23
|
Grenett HE, Eipers PG, Kidd VJ, Bounelis P, Fuller GM. Chromosomal localization of a human cDNA containing a DIDS binding domain and demonstrating high homology to yeast omnipotent suppressor 45. SOMATIC CELL AND MOLECULAR GENETICS 1992; 18:97-102. [PMID: 1546371 DOI: 10.1007/bf01233452] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We recently have identified a full-length cDNA (TB3-1) from a human adenocarcinoma cell line T84 cDNA library that encodes a 47.8-kDa protein. TB3-1 shares identity with the putative yeast translation termination factor omnipotent suppressor 45. Using human-mouse somatic cell panel analysis, a family of sequences with high homology to the TB3-1 cDNA clone were localized to human chromosomes 5, 6, 7, and X. Southern analysis of a panel of mammalian and chicken genomic DNA demonstrates that TB3-1 is well conserved in higher vertebrates.
Collapse
MESH Headings
- 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid
- 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid/analogs & derivatives
- 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid/metabolism
- Amino Acid Sequence
- Animals
- Binding Sites
- Chickens
- Chromosome Mapping
- Chromosomes, Human/chemistry
- Chromosomes, Human, Pair 6/chemistry
- Chromosomes, Human, Pair 7/chemistry
- Cricetinae
- Cricetulus
- DNA/analysis
- Genes, Suppressor
- Humans
- Mice
- Molecular Sequence Data
- Saccharomyces cerevisiae/genetics
- Sequence Homology, Nucleic Acid
- Species Specificity
- X Chromosome/chemistry
Collapse
Affiliation(s)
- H E Grenett
- Department of Cell Biology, University of Alabama, Birmingham
| | | | | | | | | |
Collapse
|
24
|
Dagkesamanskaya AR, Ter-Avanesyan MD. Interaction of the yeast omnipotent suppressors SUP1(SUP45) and SUP2(SUP35) with non-mendelian factors. Genetics 1991; 128:513-20. [PMID: 1874413 PMCID: PMC1204525 DOI: 10.1093/genetics/128.3.513] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The SUP1 and SUP2 genes code for protein factors intimately involved in the control of translational accuracy. The disrupted alleles of these genes confer a recessive lethal phenotype in both [psi+] and [psi-] genetic backgrounds, indicating an essential function for the corresponding proteins. In [psi+] diploids, heterozygous for the SUP1 null allele, several dominant phenotypes were evident with slow growth and inability to sporulate. These dominant phenotypes disappear after transformation with the multicopy plasmid carrying the wild-type allele of the SUP1 gene. Such dominant phenotypes were not observed for the SUP2 null allele. The incompatibility of multicopy plasmids carrying the SUP2 gene with guanidine hydrochloride-curable cytoplasmic factor(s) was also demonstrated. The possible mechanisms of interaction of the SUP1 and SUP2 genes with the [psi] determinant are discussed.
Collapse
Affiliation(s)
- A R Dagkesamanskaya
- Institute of Experimental Cardiology, USSR Cardiology Research Center, Moscow
| | | |
Collapse
|
25
|
Didichenko SA, Ter-Avanesyan MD, Smirnov VN. Ribosome-bound EF-1 alpha-like protein of yeast Saccharomyces cerevisiae. EUROPEAN JOURNAL OF BIOCHEMISTRY 1991; 198:705-11. [PMID: 2050148 DOI: 10.1111/j.1432-1033.1991.tb16070.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The SUP2 (SUP35) omnipotent suppressor gene encodes the EF-1 alpha-like polypeptide, intimately involved in the control of translational ambiguity in the yeast Saccharomyces cerevisiae. The present study is devoted to the immunological characterization of the Sup2 protein. The SUP2 gene was fused to the Escherichia coli lacZ gene and a polyclonal antibody against the corresponding Sup2--beta-galactosidase hybrid protein was obtained. This antibody identified a 79-kDa protein that was absent in those cells where the SUP2 gene was disrupted, and an abundance of this protein was observed in cells overexpressing the SUP2 gene. The localization of this protein was studied in subcellular fractionation experiments. The SUP2 gene product proved to be uniformly distributed throughout ribosome-enriched samples, i.e. free polysomes, crude microsomes and rough endoplasmic reticulum. It was not found in the cytoplasm and smooth endoplasmic reticulum. The SUP2-encoded protein was fully ribosome associated and less abundant than the ribosomal protein L3. Also, in a sucrose gradient, Sup2 preferentially cosedimented with the 40S ribosomal subunit, but not with the 60S subunit. The functional significance of this association is discussed.
Collapse
Affiliation(s)
- S A Didichenko
- Institute of Experimental Cardiology, USSR Cardiology Research Center, Moscow
| | | | | |
Collapse
|
26
|
Abstract
A physical map of the Saccharomyces cerevisiae genome is presented. It was derived by mapping the sites for two restriction endonucleases, SfiI and NotI, each of which recognizes an 8-bp sequence. DNA-DNA hybridization probes for genetically mapped genes and probes that span particular SfiI and NotI sites were used to construct a map that contains 131 physical landmarks--32 chromosome ends, 61 SfiI sites and 38 NotI sites. These landmarks are distributed throughout the non-rDNA component of the yeast genome, which comprises 12.5 Mbp of DNA. The physical map suggests that those genes that can be detected and mapped by standard genetic methods are distributed rather uniformly over the full physical extent of the yeast genome. The map has immediate applications to the mapping of genes for which single-copy DNA-DNA hybridization probes are available.
Collapse
Affiliation(s)
- A J Link
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri 63110
| | | |
Collapse
|
27
|
Himmelfarb HJ, Pearlberg J, Last DH, Ptashne M. GAL11P: a yeast mutation that potentiates the effect of weak GAL4-derived activators. Cell 1990; 63:1299-309. [PMID: 2124519 DOI: 10.1016/0092-8674(90)90425-e] [Citation(s) in RCA: 126] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A mutant yeast in which a weak GAL4-derived activator functions as a strong activator bears a single mis-sense mutation in GAL11 (a.k.a. SPT13). The first 74 amino acids of GAL4, including the zinc-dependent DNA binding region, attached to an acidic activating sequence, are sufficient to respond both to GAL11 and to our mutant GAL11P (potentiator). PPR1, a yeast activator with a similar zinc finger sequence, also responds to GAL11 and to GAL11P, whereas regulators bearing unrelated DNA binding motifs do not. GAL11 itself works as a strong activator when tethered to DNA by fusion to the bacterial LexA protein, and deletion of GAL11 is known to cause a 5- to 10-fold reduction in GAL4 activity. We suggest that a complex of GAL4 and GAL11 constitutes a particularly strong activator; evidence that the putative GAL4-GAL11 complex ordinarily forms preferentially on DNA suggests a biological rationale for GAL11 action.
Collapse
Affiliation(s)
- H J Himmelfarb
- Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, Massachusetts 02138
| | | | | | | |
Collapse
|
28
|
Pocklington MJ, Johnston L, Jenkins JR, Orr E. The omnipotent suppressor SUP45 affects nucleic acid metabolism and mitochondrial structure. Yeast 1990; 6:441-50. [PMID: 2220077 DOI: 10.1002/yea.320060509] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Yeast (Saccharomyces cerevisiae) strains sensitive to a variety of drugs were used to select for novobiocin-resistant mutants that were simultaneously temperature-sensitive. The mutants remained as sensitive as the parent strains to a wide range of drugs other than novobiocin, and did not exhibit any suppression of suppressible auxotrophic markers. At the non-permissive temperature, the mutant cells arrested mainly as unbudded cells, and were instantly defective in DNA and RNA synthesis, but not protein synthesis. The cloned wild-type gene was identified as SUP45, which has been previously implicated in the translation process. Our results suggest that SUP45 may have a function in addition to, or different from, the one that has been assigned to it previously.
Collapse
MESH Headings
- Cloning, Molecular
- DNA, Fungal/biosynthesis
- DNA, Fungal/drug effects
- DNA, Mitochondrial/biosynthesis
- Drug Resistance, Microbial
- Fungal Proteins/biosynthesis
- Fungal Proteins/drug effects
- Genes, Fungal
- Genes, Suppressor/physiology
- Microscopy, Fluorescence
- Mitochondria/ultrastructure
- Mutation
- Novobiocin/pharmacology
- Phenotype
- RNA, Fungal/biosynthesis
- RNA, Fungal/drug effects
- Restriction Mapping
- Saccharomyces cerevisiae/drug effects
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
Collapse
|
29
|
Wakem LP, Sherman F. Isolation and characterization of omnipotent suppressors in the yeast Saccharomyces cerevisiae. Genetics 1990; 124:515-22. [PMID: 2179051 PMCID: PMC1203945 DOI: 10.1093/genetics/124.3.515] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Approximately 290 omnipotent suppressors, which enhance translational misreading, were isolated in strains of the yeast Saccharomyces cerevisiae containing the psi+ extrachromosomal determinant. The suppressors could be assigned to 8 classes by their pattern of suppression of five nutritional markers. The suppressors were further distinguished by differences in growth on paromomycin medium, hypertonic medium, low temperatures (10 degrees), nonfermentable carbon sources, alpha-aminoadipic acid medium, and by their dominance and recessiveness. Genetic analysis of 12 representative suppressors resulted in the assignment of these suppressors to 6 different loci, including the three previously described loci SUP35 (chromosome IV), SUP45 (chromosome II) and SUP46 (chromosome II), as well as three new loci SUP42 (chromosome IV), SUP43 (chromosome XV) and SUP44 (chromosome VII). Suppressors belonging to the same locus had a wide range of different phenotypes. Differences between alleles of the same locus and similarities between alleles of different loci suggest that the omnipotent suppressors encode proteins that effect different functions and that altered forms of each of the proteins can effect the same function.
Collapse
Affiliation(s)
- L P Wakem
- Department of Biochemistry, University of Rochester School of Medicine and Dentistry, New York 14642
| | | |
Collapse
|
30
|
Ono B, Tanaka M, Awano I, Okamoto F, Satoh R, Yamagishi N, Ishino-Arao Y. Two new loci that give rise to dominant omnipotent suppressors in Saccharomyces cerevisiae. Curr Genet 1989; 16:323-30. [PMID: 2692850 DOI: 10.1007/bf00340710] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Ten dominant omnipotent suppressors of Saccharomyces cerevisiae, which were previously shown to be different from SUP46, have been examined. Nine are mapped in a region between lys5 and cyh2 on the left arm of chromosome VII. These suppressors, like SUP46, manifest sensitivity to increased temperature and the antibiotics paromomycin and hygromycin B. In addition, they have an identical action spectrum. These results strongly suggest that they are allelic to each other and they are designated SUP138. The tenth is mapped to a position between his1 and arg6 on the right arm of chromosome V. This suppressor, named SUP139, does not manifest temperature sensitivity nor antibiotic sensitivity. SUP139 and SUP138, which are clearly distinguished by means of action spectrum, act on much fewer nonsense mutations than SUP46. It is now clear that dominant omnipotent suppressors arising at a single locus are homogeneous and that their efficiency is locus-dependent. The order of efficiency is SUP46 greater than SUP138 greater than SUP139.
Collapse
Affiliation(s)
- B Ono
- Laboratory of Environmental Hygiene Chemistry, Faculty of Pharmaceutical Sciences, Okayama University, Japan
| | | | | | | | | | | | | |
Collapse
|
31
|
Balzi E, Chen WN, Capieaux E, McCusker JH, Haber JE, Goffeau A. The suppressor gene scl1+ of Saccharomyces cerevisiae is essential for growth. Gene 1989; 83:271-9. [PMID: 2684789 DOI: 10.1016/0378-1119(89)90113-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In Saccharomyces cerevisiae, the SCL-1 mutation is a dominant suppressor of the cycloheximide-resistant, temperature-sensitive (ts) lethal mutation, crl3 [McCusker and Haber, Genetics 119 (1988a) 303-315]. The wild-type scl1+ gene was isolated by screening subclones of the 35-kb region between TRP5 and LEU1 for restoration of the ts phenotype in an SCL1-1 crl3-2 strain. The scl1+ mRNA is about 900 nt long and encodes an open reading frame of 810 bp. The polypeptide deduced from scl1+ possesses a putative secretory signal peptide. The 5'-noncoding region may be under multiple controls, since it contains significant homology to the consensus sequences for the DNA-binding proteins, GCN4, GFI and, possibly, TUF. Gene disruption of scl1+ demonstrates that it is an essential gene.
Collapse
Affiliation(s)
- E Balzi
- Unité de Biochimie Physiologique, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | | | | | | | | | | |
Collapse
|
32
|
Gellerfors P, Axelsson K, Helander A, Johansson S, Kenne L, Lindqvist S, Pavlu B, Skottner A, Fryklund L. Isolation and Characterization of a Glycosylated Form of Human Insulin-like Growth Factor I Produced in Saccharomyces cerevisiae. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)60484-3] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
33
|
Crouzet M, Izgu F, Grant CM, Tuite MF. The allosuppressor gene SAL4 encodes a protein important for maintaining translational fidelity in Saccharomyces cerevisiae. Curr Genet 1988; 14:537-43. [PMID: 3072098 DOI: 10.1007/bf00434078] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Allosuppressor (sal) mutations enhance the efficiency of the yeast ochre suppressor SUQ5 and define five unlinked loci, SAL1-SAL5. A number of sal4 mutants were isolated and found to have pleiotropic, allele;specific phenotypes, including hypersensitivity in vivo to paromomycin and other antibiotics that stimulate translational errors in yeast. To examine further the nature of the SAL4 gene product, the wild type SAL4 gene was isolated by complementation of a conditional lethal allele sal4-2, and demonstrated to be a single copy gene encoding a single 1.6 kb transcript. Restriction mapping and DNA hybridisation analysis were used to demonstrate that the SAL4 gene is identical to the previously identified omnipotent suppressor gene SUP45 (SUP1). Our results implicate the SAL4 gene product as playing a major role in maintaining translational accuracy in yeast.
Collapse
Affiliation(s)
- M Crouzet
- Biological Laboratory, University of Canterbury, Kent, UK
| | | | | | | |
Collapse
|
34
|
Modifiers of ochre suppressors in Saccharomyces cerevisiae that exhibit ochre suppressor-dependent amber suppression. Curr Genet 1988. [DOI: 10.1007/bf00419992] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
35
|
McCusker JH, Haber JE. crl mutants of Saccharomyces cerevisiae resemble both mutants affecting general control of amino acid biosynthesis and omnipotent translational suppressor mutants. Genetics 1988; 119:317-27. [PMID: 3294104 PMCID: PMC1203414 DOI: 10.1093/genetics/119.2.317] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Cyocloheximide resistant lethal (crl) mutants of Saccharomyces cerevisiae, defining 22 unlinked complementation groups, are unable to grow at 37 degrees. They are also highly pleiotropic at their permissive temperature of 25 degrees. The mutants are all unable to arrest at the G1 stage of the cell cycle when grown to stationary phase or when starved for a single amino acid, though they do arrest at G1 when deprived of all nitrogen. The crl mutants are also hypersensitive to various amino acid analogs and to 3-aminotriazole. These mutants also "tighten" leaky auxotrophic mutations that permit wild-type cells to grow in the absence of the appropriate amino acid. All of these phenotypes are also exhibited by gcn mutants affecting general control of amino acid biosynthesis. In addition, the crl mutants are all hypersensitive to hygromycin B, an aminoglycoside antibiotic that stimulates translational misreading. The crl mutations also suppress one nonsense mutation which is phenotypically suppressed by hygromycin B. Many crl mutants are also osmotically sensitive. These are phenotypes which the crl mutations have in common with previously isolated omnipotent suppressors. We suggest that the the crl mutations all affect the fidelity of protein translation.
Collapse
Affiliation(s)
- J H McCusker
- Department of Biology, Brandeis University, Waltham, Massachusetts 02254
| | | |
Collapse
|
36
|
|
37
|
Wilson PG, Culbertson MR. SUF12 suppressor protein of yeast. A fusion protein related to the EF-1 family of elongation factors. J Mol Biol 1988; 199:559-73. [PMID: 3280807 DOI: 10.1016/0022-2836(88)90301-4] [Citation(s) in RCA: 99] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Mutations at the suf12 locus were isolated in Saccharomyces cerevisiae as extragenic suppressors of +1 frameshift mutations in glycine (GGX) and proline (CCX) codons, as well as UGA and UAG nonsense mutations. To identify the SUF12 function in translation and to understand the relationship between suf12-mediated misreading and translational frameshifting, we have isolated an SUF12+ clone from a centromeric plasmid library by complementation. SUF12+ is an essential, single-copy gene that is identical with the omnipotent suppressor gene SUP35+. The 2.3 x 10(3) base SUF12+ transcript contains an open reading frame sufficient to encode a 88 x 10(3) Mr protein. The pattern of codon usage and transcript abundance suggests that SUF12+ is not a highly expressed gene. The linear SUF12 amino acid sequence suggests that SUF12 has evolved as a fusion protein of unique N-terminal domains fused to domains that exhibit essentially co-linear homology to the EF-1 family of elongation factors. Beginning internally at amino acid 254, homology is more extensive between the SUF12 protein and EF-1 alpha of yeast (36% identity; 65% with conservative substitutions) than between EF-1 alpha of yeast and EF-Tu of Escherichia coli. The most extensive regions of SUF12/EF-1 alpha homology are those regions that have been conserved in the EF-1 family, including domains involved in GTP and tRNA binding. It is clear that SUF12 and EF-1 alpha are not functionally equivalent, since both are essential in vivo. The N-terminal domains of SUF12 are unique and may reflect, in part, the functional distinction between these proteins. These domains exhibit unusual amino acid composition and extensive repeated structure. The behavior of suf12-null/SUF12+ heterozygotes indicates that suf12 is co-dominantly expressed and suggests that suf12 allele-specific suppression may result from functionally distinct mutant proteins rather than variation in residual wild-type SUF12+ activity. We propose a model of suf12-mediated frameshift and nonsense suppression that is based on a primary defect in the normal process of codon recognition.
Collapse
Affiliation(s)
- P G Wilson
- Laboratory of Genetics, University of Wisconsin, Madison 53706
| | | |
Collapse
|
38
|
Kushnirov VV, Ter-Avanesyan MD, Surguchov AP, Smirnov VN, Inge-Vechtomov SG. Localization of possible functional domains in sup2 gene product of the yeast Saccharomyces cerevisiae. FEBS Lett 1987; 215:257-60. [PMID: 3556215 DOI: 10.1016/0014-5793(87)80157-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Primary structures of yeast sup2 gene and polypeptide product coded by the gene are compared with the current nucleotide and amino acid sequence data base. The amino acid sequence of the sup2 product shows homology to elongation factors from different sources. Especially high homology is found in the regions, corresponding to conservative aminoacyl-tRNA- and GTP-binding domains, described in elongation factors and other proteins. The data obtained are discussed in relation to the functions of sup2 polypeptide product in protein synthesis.
Collapse
|
39
|
Ernst JF. Improved secretion of heterologous proteins by Saccharomyces cerevisiae: effects of promoter substitution in alpha-factor fusions. DNA (MARY ANN LIEBERT, INC.) 1986; 5:483-91. [PMID: 3028738 DOI: 10.1089/dna.1.1986.5.483] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effects of promoter strength on secretion of a heterologous protein, somatomedin-C (SMC), by the yeast Saccharomyces cerevisiae were studied by using the promoters of the MF alpha 1, ACT, and CYC1 genes to control expression of alpha-factor/SMC gene fusions. When a low-copy centromere vector was used to carry the gene fusions in yeast transformants, the greatest secretion was obtained with the MF alpha 1 promoter construction and the least with the CYC1 promoter construction. Unexpectedly, using two types of multicopy vectors, the greatest secretion was obtained with the CYC1 promoter construction and the least with the MF alpha 1 promoter construction. The decrease in secretion by the strongest promoter construction (MF alpha 1 promoter) on multicopy vectors was associated with a decrease in SMC mRNA during growth, a decrease in vector copy number, a decrease in vector stability, and a decrease in transformation frequency. The results demonstrate that, unlike in intracellular expression, promoter strength is not simply related to secretion expression levels. Selection against oversecreting cells during growth may explain the reduced secretion efficiency of strong promoter constructions.
Collapse
|
40
|
Surguchov AP, Telkov MV, Smirnov VN. Absence of structural homology between sup1 and sup2 genes of yeast Saccharomyces cerevisiae and identification of their transcripts. FEBS Lett 1986; 206:147-50. [PMID: 3019765 DOI: 10.1016/0014-5793(86)81357-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The results of Southern blotting demonstrate that sup2 is a unique gene in Saccharomyces cerevisiae that does not possess homologous sequences in the yeast genome. The direct hybridization of DNA fragments, containing cloned sup1 and sup2 genes, did not reveal any structural homology between these two genes. By Northern blotting analysis the sizes of the transcripts were determined to be 1.6 kb for sup1 gene and 2.5 and 1.4kb for sup2 gene. Experiments with RNA isolated from yeast mutant with impaired splicing demonstrated that sup1 and sup2 genes do not contain introns.
Collapse
|
41
|
Fouser LA, Friesen JD. Mutations in a yeast intron demonstrate the importance of specific conserved nucleotides for the two stages of nuclear mRNA splicing. Cell 1986; 45:81-93. [PMID: 3513966 DOI: 10.1016/0092-8674(86)90540-4] [Citation(s) in RCA: 129] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Mutations were introduced at all positions of the internal conserved sequence (ICS) and at three positions in the 5' junction sequence of a Saccharomyces cerevisiae actin intron contained within an actin-thymidine kinase fusion gene. Stage I of splicing is reduced by changes at all these positions. C or A replacement at the fifth nucleotide of the 5' sequence reduces the fidelity of RNA cleavage at the 5' exon-intron junction and results in an accumulation of aberrant lariat intermediate. Stage II of splicing is affected by changes in the first and second residues of the 5' sequence and in the penultimate position of the ICS. An A to G transition at the branch point of the ICS causes a major accumulation of lariat intermediate.
Collapse
|
42
|
Eustice DC, Wakem LP, Wilhelm JM, Sherman F. Altered 40 S ribosomal subunits in omnipotent suppressors of yeast. J Mol Biol 1986; 188:207-14. [PMID: 3522920 DOI: 10.1016/0022-2836(86)90305-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The five suppressors SUP35, SUP43, SUP44, SUP45 and SUP46, each mapping at a different chromosomal locus in the yeast Saccharomyces cerevisiae, suppress a wide range of mutations, including representatives of all three types of nonsense mutations, UAA, UAG and UGA. We have demonstrated that ribosomes from the four suppressors SUP35, SUP44, SUP45 and SUP46 translate polyuridylate templates in vitro with higher errors than ribosomes from the normal stain, and that this misreading is substantially enhanced by the antibiotic paromomycin. Furthermore, ribosomal subunit mixing experiments established that the 40 S ribosomal subunit, and this subunit only, is responsible for the higher levels of misreading. Thus, the gene products of SUP35, SUP44, SUP45 and SUP46 are components of the 40 S subunit or are enzymes that modify the subunit. In addition, a protein from the 40 S subunit of the SUP35 suppressor has an altered electrophoretic mobility; this protein is distinct from the altered protein previously uncovered in the 40 S subunit of the SUP46 suppressor. In contrast to the ribosomes from the four suppressors SUP35, SUP44, SUP45 and SUP46, the ribosomes from the SUP43 suppressor do not significantly misread polyuridylate templates in vitro, suggesting that this locus may not encode a ribosomal component or that the misreading is highly specific.
Collapse
|