Skip to main content
PMC home page
The EMBO Journal logoLink to The EMBO Journal
. 1988 Nov;7(11):3547–3551. doi: 10.1002/j.1460-2075.1988.tb03231.x

Evidence that the GCN2 protein kinase regulates reinitiation by yeast ribosomes.

D Tzamarias 1, G Thireos 1
PMCID: PMC454856  PMID: 3061799

Abstract

The yeast gene GCN4 produces an mRNA that has a long 5' 'untranslated' region containing four small open reading frames (ORFs) preceding the protein coding frame. This configuration suppresses the rate by which GCN4 protein is synthesized. However, translational derepression of the GCN4 mRNA occurs when yeast cells are grown under conditions of amino acid limitation. Such translational derepression requires the GCN2 protein kinase and the presence of the 5' most proximal ORF. In this study we show that a functional coupling between the translation of the first ORF and the amount of the GCN2 protein is responsible for the translational derepression of the GCN4 mRNA. Our evidence suggests that this coupling involves an increase in the ability of 40S ribosomal subunits that have translated the first frame to resume scanning and reinitiate translation at a downstream AUG independently of the base sequence in the intervening region.

Full text

PDF
3549

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Cigan A. M., Donahue T. F. Sequence and structural features associated with translational initiator regions in yeast--a review. Gene. 1987;59(1):1–18. doi: 10.1016/0378-1119(87)90261-7. [DOI] [PubMed] [Google Scholar]
  2. Hamilton R., Watanabe C. K., de Boer H. A. Compilation and comparison of the sequence context around the AUG startcodons in Saccharomyces cerevisiae mRNAs. Nucleic Acids Res. 1987 Apr 24;15(8):3581–3593. doi: 10.1093/nar/15.8.3581. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Hinnebusch A. G. A hierarchy of trans-acting factors modulates translation of an activator of amino acid biosynthetic genes in Saccharomyces cerevisiae. Mol Cell Biol. 1985 Sep;5(9):2349–2360. doi: 10.1128/mcb.5.9.2349. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Hinnebusch A. G. Evidence for translational regulation of the activator of general amino acid control in yeast. Proc Natl Acad Sci U S A. 1984 Oct;81(20):6442–6446. doi: 10.1073/pnas.81.20.6442. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Hope I. A., Struhl K. GCN4 protein, synthesized in vitro, binds HIS3 regulatory sequences: implications for general control of amino acid biosynthetic genes in yeast. Cell. 1985 Nov;43(1):177–188. doi: 10.1016/0092-8674(85)90022-4. [DOI] [PubMed] [Google Scholar]
  6. Hughes S., Mellstrom K., Kosik E., Tamanoi F., Brugge J. Mutation of a termination codon affects src initiation. Mol Cell Biol. 1984 Sep;4(9):1738–1746. doi: 10.1128/mcb.4.9.1738. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Kozak M. Effects of intercistronic length on the efficiency of reinitiation by eucaryotic ribosomes. Mol Cell Biol. 1987 Oct;7(10):3438–3445. doi: 10.1128/mcb.7.10.3438. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Kozak M. Inability of circular mRNA to attach to eukaryotic ribosomes. Nature. 1979 Jul 5;280(5717):82–85. doi: 10.1038/280082a0. [DOI] [PubMed] [Google Scholar]
  9. Kozak M. Point mutations define a sequence flanking the AUG initiator codon that modulates translation by eukaryotic ribosomes. Cell. 1986 Jan 31;44(2):283–292. doi: 10.1016/0092-8674(86)90762-2. [DOI] [PubMed] [Google Scholar]
  10. Kozak M. Selection of initiation sites by eucaryotic ribosomes: effect of inserting AUG triplets upstream from the coding sequence for preproinsulin. Nucleic Acids Res. 1984 May 11;12(9):3873–3893. doi: 10.1093/nar/12.9.3873. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Liu C. C., Simonsen C. C., Levinson A. D. Initiation of translation at internal AUG codons in mammalian cells. Nature. 1984 May 3;309(5963):82–85. doi: 10.1038/309082a0. [DOI] [PubMed] [Google Scholar]
  12. Mueller P. P., Harashima S., Hinnebusch A. G. A segment of GCN4 mRNA containing the upstream AUG codons confers translational control upon a heterologous yeast transcript. Proc Natl Acad Sci U S A. 1987 May;84(9):2863–2867. doi: 10.1073/pnas.84.9.2863. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Mueller P. P., Hinnebusch A. G. Multiple upstream AUG codons mediate translational control of GCN4. Cell. 1986 Apr 25;45(2):201–207. doi: 10.1016/0092-8674(86)90384-3. [DOI] [PubMed] [Google Scholar]
  14. Peabody D. S., Berg P. Termination-reinitiation occurs in the translation of mammalian cell mRNAs. Mol Cell Biol. 1986 Jul;6(7):2695–2703. doi: 10.1128/mcb.6.7.2695. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Peabody D. S., Subramani S., Berg P. Effect of upstream reading frames on translation efficiency in simian virus 40 recombinants. Mol Cell Biol. 1986 Jul;6(7):2704–2711. doi: 10.1128/mcb.6.7.2704. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Roussou I., Thireos G., Hauge B. M. Transcriptional-translational regulatory circuit in Saccharomyces cerevisiae which involves the GCN4 transcriptional activator and the GCN2 protein kinase. Mol Cell Biol. 1988 May;8(5):2132–2139. doi: 10.1128/mcb.8.5.2132. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Thireos G., Penn M. D., Greer H. 5' untranslated sequences are required for the translational control of a yeast regulatory gene. Proc Natl Acad Sci U S A. 1984 Aug;81(16):5096–5100. doi: 10.1073/pnas.81.16.5096. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Tzamarias D., Alexandraki D., Thireos G. Multiple cis-acting elements modulate the translational efficiency of GCN4 mRNA in yeast. Proc Natl Acad Sci U S A. 1986 Jul;83(13):4849–4853. doi: 10.1073/pnas.83.13.4849. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from The EMBO Journal are provided here courtesy of Nature Publishing Group

RESOURCES