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. 1996 Dec;16(12):6707–6714. doi: 10.1128/mcb.16.12.6707

The Cyc8 (Ssn6)-Tup1 corepressor complex is composed of one Cyc8 and four Tup1 subunits.

U S Varanasi 1, M Klis 1, P B Mikesell 1, R J Trumbly 1
PMCID: PMC231673  PMID: 8943325

Abstract

The Cyc8 (Ssn6)-Tup1 corepressor complex is required for repression in several important regulatory systems in yeast cells, including glucose repression and mating type. Cyc8-Tup1 is recruited to target genes by interaction with diverse repressor proteins that bind directly to DNA. Since the complex has a large apparent molecular mass of 1,200 kDa on nondenaturing gels (F. E. Williams, U. Varanasi, and R. J. Trumbly, Mol. Cell. Biol. 11:3307-3316, 1991), we used a variety of approaches to determine its actual subunit composition. Immunoprecipitation of epitope-tagged complex and reconstitution of the complex from in vitro-translated proteins demonstrated that only the Cyc8 and Tup1 proteins were present in the complex. Hydrodynamic properties showed that these proteins have unusually large Stokes radii, low sedimentation coefficients, and high frictional ratios, all characteristic of asymmetry which partly accounts for the apparent high molecular weight. Calculation of native molecular weights from these properties indicated that the Cyc8-Tup1 complex is composed of one Cyc8 subunit and four Tup1 subunits. This composition was confirmed by reconstitution of the complex from Cyc8 and Tup1 expressed in vitro and analysis by one- and two-dimensional gel electrophoresis.

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Selected References

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

  1. Balciunas D., Ronne H. Three subunits of the RNA polymerase II mediator complex are involved in glucose repression. Nucleic Acids Res. 1995 Nov 11;23(21):4421–4425. doi: 10.1093/nar/23.21.4421. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1016/0003-2697(76)90527-3. [DOI] [PubMed] [Google Scholar]
  3. Cairns B. R., Kim Y. J., Sayre M. H., Laurent B. C., Kornberg R. D. A multisubunit complex containing the SWI1/ADR6, SWI2/SNF2, SWI3, SNF5, and SNF6 gene products isolated from yeast. Proc Natl Acad Sci U S A. 1994 Mar 1;91(5):1950–1954. doi: 10.1073/pnas.91.5.1950. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Chen J. D., Evans R. M. A transcriptional co-repressor that interacts with nuclear hormone receptors. Nature. 1995 Oct 5;377(6548):454–457. doi: 10.1038/377454a0. [DOI] [PubMed] [Google Scholar]
  5. Cooper J. P., Roth S. Y., Simpson R. T. The global transcriptional regulators, SSN6 and TUP1, play distinct roles in the establishment of a repressive chromatin structure. Genes Dev. 1994 Jun 15;8(12):1400–1410. doi: 10.1101/gad.8.12.1400. [DOI] [PubMed] [Google Scholar]
  6. Côté J., Quinn J., Workman J. L., Peterson C. L. Stimulation of GAL4 derivative binding to nucleosomal DNA by the yeast SWI/SNF complex. Science. 1994 Jul 1;265(5168):53–60. doi: 10.1126/science.8016655. [DOI] [PubMed] [Google Scholar]
  7. Edmondson D. G., Smith M. M., Roth S. Y. Repression domain of the yeast global repressor Tup1 interacts directly with histones H3 and H4. Genes Dev. 1996 May 15;10(10):1247–1259. doi: 10.1101/gad.10.10.1247. [DOI] [PubMed] [Google Scholar]
  8. Errede B., Ammerer G. STE12, a protein involved in cell-type-specific transcription and signal transduction in yeast, is part of protein-DNA complexes. Genes Dev. 1989 Sep;3(9):1349–1361. doi: 10.1101/gad.3.9.1349. [DOI] [PubMed] [Google Scholar]
  9. Goebl M., Yanagida M. The TPR snap helix: a novel protein repeat motif from mitosis to transcription. Trends Biochem Sci. 1991 May;16(5):173–177. doi: 10.1016/0968-0004(91)90070-c. [DOI] [PubMed] [Google Scholar]
  10. Gutjahr T., Frei E., Spicer C., Baumgartner S., White R. A., Noll M. The Polycomb-group gene, extra sex combs, encodes a nuclear member of the WD-40 repeat family. EMBO J. 1995 Sep 1;14(17):4296–4306. doi: 10.1002/j.1460-2075.1995.tb00104.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Herschbach B. M., Arnaud M. B., Johnson A. D. Transcriptional repression directed by the yeast alpha 2 protein in vitro. Nature. 1994 Jul 28;370(6487):309–311. doi: 10.1038/370309a0. [DOI] [PubMed] [Google Scholar]
  12. Herskowitz I. A regulatory hierarchy for cell specialization in yeast. Nature. 1989 Dec 14;342(6251):749–757. doi: 10.1038/342749a0. [DOI] [PubMed] [Google Scholar]
  13. Hirano T., Kinoshita N., Morikawa K., Yanagida M. Snap helix with knob and hole: essential repeats in S. pombe nuclear protein nuc2+. Cell. 1990 Jan 26;60(2):319–328. doi: 10.1016/0092-8674(90)90746-2. [DOI] [PubMed] [Google Scholar]
  14. Hoheisel J. D. A cassette with seven unique restriction sites, including octanucleotide sequences: extension of multiple-cloning-site plasmids. Gene. 1989 Aug 1;80(1):151–154. doi: 10.1016/0378-1119(89)90260-6. [DOI] [PubMed] [Google Scholar]
  15. Hörlein A. J., När A. M., Heinzel T., Torchia J., Gloss B., Kurokawa R., Ryan A., Kamei Y., Söderström M., Glass C. K. Ligand-independent repression by the thyroid hormone receptor mediated by a nuclear receptor co-repressor. Nature. 1995 Oct 5;377(6548):397–404. doi: 10.1038/377397a0. [DOI] [PubMed] [Google Scholar]
  16. Ito H., Fukuda Y., Murata K., Kimura A. Transformation of intact yeast cells treated with alkali cations. J Bacteriol. 1983 Jan;153(1):163–168. doi: 10.1128/jb.153.1.163-168.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Keleher C. A., Redd M. J., Schultz J., Carlson M., Johnson A. D. Ssn6-Tup1 is a general repressor of transcription in yeast. Cell. 1992 Feb 21;68(4):709–719. doi: 10.1016/0092-8674(92)90146-4. [DOI] [PubMed] [Google Scholar]
  18. Kolodziej P. A., Young R. A. Epitope tagging and protein surveillance. Methods Enzymol. 1991;194:508–519. doi: 10.1016/0076-6879(91)94038-e. [DOI] [PubMed] [Google Scholar]
  19. Komachi K., Redd M. J., Johnson A. D. The WD repeats of Tup1 interact with the homeo domain protein alpha 2. Genes Dev. 1994 Dec 1;8(23):2857–2867. doi: 10.1101/gad.8.23.2857. [DOI] [PubMed] [Google Scholar]
  20. Kuchin S., Yeghiayan P., Carlson M. Cyclin-dependent protein kinase and cyclin homologs SSN3 and SSN8 contribute to transcriptional control in yeast. Proc Natl Acad Sci U S A. 1995 Apr 25;92(9):4006–4010. doi: 10.1073/pnas.92.9.4006. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Kunkel T. A., Bebenek K., McClary J. Efficient site-directed mutagenesis using uracil-containing DNA. Methods Enzymol. 1991;204:125–139. doi: 10.1016/0076-6879(91)04008-c. [DOI] [PubMed] [Google Scholar]
  22. Lamb J. R., Michaud W. A., Sikorski R. S., Hieter P. A. Cdc16p, Cdc23p and Cdc27p form a complex essential for mitosis. EMBO J. 1994 Sep 15;13(18):4321–4328. doi: 10.1002/j.1460-2075.1994.tb06752.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Mead D. A., Szczesna-Skorupa E., Kemper B. Single-stranded DNA 'blue' T7 promoter plasmids: a versatile tandem promoter system for cloning and protein engineering. Protein Eng. 1986 Oct-Nov;1(1):67–74. doi: 10.1093/protein/1.1.67. [DOI] [PubMed] [Google Scholar]
  24. Murphy M. R., Shimizu M., Roth S. Y., Dranginis A. M., Simpson R. T. DNA-protein interactions at the S.cerevisiae alpha 2 operator in vivo. Nucleic Acids Res. 1993 Jul 11;21(14):3295–3300. doi: 10.1093/nar/21.14.3295. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Neer E. J., Schmidt C. J., Nambudripad R., Smith T. F. The ancient regulatory-protein family of WD-repeat proteins. Nature. 1994 Sep 22;371(6495):297–300. doi: 10.1038/371297a0. [DOI] [PubMed] [Google Scholar]
  26. Nehlin J. O., Ronne H. Yeast MIG1 repressor is related to the mammalian early growth response and Wilms' tumour finger proteins. EMBO J. 1990 Sep;9(9):2891–2898. doi: 10.1002/j.1460-2075.1990.tb07479.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Ozcan S., Johnston M. Three different regulatory mechanisms enable yeast hexose transporter (HXT) genes to be induced by different levels of glucose. Mol Cell Biol. 1995 Mar;15(3):1564–1572. doi: 10.1128/mcb.15.3.1564. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Paroush Z., Finley R. L., Jr, Kidd T., Wainwright S. M., Ingham P. W., Brent R., Ish-Horowicz D. Groucho is required for Drosophila neurogenesis, segmentation, and sex determination and interacts directly with hairy-related bHLH proteins. Cell. 1994 Dec 2;79(5):805–815. doi: 10.1016/0092-8674(94)90070-1. [DOI] [PubMed] [Google Scholar]
  29. Roth S. Y., Dean A., Simpson R. T. Yeast alpha 2 repressor positions nucleosomes in TRP1/ARS1 chromatin. Mol Cell Biol. 1990 May;10(5):2247–2260. doi: 10.1128/mcb.10.5.2247. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Rothe G. M., Weidmann H. Computer-aided calculation of the molecular size of nondenatured proteins in pore-gradient gel electrophoresis. Electrophoresis. 1991 Oct;12(10):703–709. doi: 10.1002/elps.1150121004. [DOI] [PubMed] [Google Scholar]
  31. Rothstein R. J., Sherman F. Genes affecting the expression of cytochrome c in yeast: genetic mapping and genetic interactions. Genetics. 1980 Apr;94(4):871–889. doi: 10.1093/genetics/94.4.871. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Schultz J., Carlson M. Molecular analysis of SSN6, a gene functionally related to the SNF1 protein kinase of Saccharomyces cerevisiae. Mol Cell Biol. 1987 Oct;7(10):3637–3645. doi: 10.1128/mcb.7.10.3637. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Schultz J., Marshall-Carlson L., Carlson M. The N-terminal TPR region is the functional domain of SSN6, a nuclear phosphoprotein of Saccharomyces cerevisiae. Mol Cell Biol. 1990 Sep;10(9):4744–4756. doi: 10.1128/mcb.10.9.4744. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Siegel L. M., Monty K. J. Determination of molecular weights and frictional ratios of proteins in impure systems by use of gel filtration and density gradient centrifugation. Application to crude preparations of sulfite and hydroxylamine reductases. Biochim Biophys Acta. 1966 Feb 7;112(2):346–362. doi: 10.1016/0926-6585(66)90333-5. [DOI] [PubMed] [Google Scholar]
  35. Smith R. L., Redd M. J., Johnson A. D. The tetratricopeptide repeats of Ssn6 interact with the homeo domain of alpha 2. Genes Dev. 1995 Dec 1;9(23):2903–2910. doi: 10.1101/gad.9.23.2903. [DOI] [PubMed] [Google Scholar]
  36. Thompson C. C., Brown T. A., McKnight S. L. Convergence of Ets- and notch-related structural motifs in a heteromeric DNA binding complex. Science. 1991 Aug 16;253(5021):762–768. doi: 10.1126/science.1876833. [DOI] [PubMed] [Google Scholar]
  37. Treitel M. A., Carlson M. Repression by SSN6-TUP1 is directed by MIG1, a repressor/activator protein. Proc Natl Acad Sci U S A. 1995 Apr 11;92(8):3132–3136. doi: 10.1073/pnas.92.8.3132. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. Trumbly R. J. Cloning and characterization of the CYC8 gene mediating glucose repression in yeast. Gene. 1988 Dec 15;73(1):97–111. doi: 10.1016/0378-1119(88)90316-2. [DOI] [PubMed] [Google Scholar]
  39. Trumbly R. J. Isolation of Saccharomyces cerevisiae mutants constitutive for invertase synthesis. J Bacteriol. 1986 Jun;166(3):1123–1127. doi: 10.1128/jb.166.3.1123-1127.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Tzamarias D., Struhl K. Distinct TPR motifs of Cyc8 are involved in recruiting the Cyc8-Tup1 corepressor complex to differentially regulated promoters. Genes Dev. 1995 Apr 1;9(7):821–831. doi: 10.1101/gad.9.7.821. [DOI] [PubMed] [Google Scholar]
  41. Tzamarias D., Struhl K. Functional dissection of the yeast Cyc8-Tup1 transcriptional co-repressor complex. Nature. 1994 Jun 30;369(6483):758–761. doi: 10.1038/369758a0. [DOI] [PubMed] [Google Scholar]
  42. Westwood J. T., Wu C. Activation of Drosophila heat shock factor: conformational change associated with a monomer-to-trimer transition. Mol Cell Biol. 1993 Jun;13(6):3481–3486. doi: 10.1128/mcb.13.6.3481. [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. Williams F. E., Trumbly R. J. Characterization of TUP1, a mediator of glucose repression in Saccharomyces cerevisiae. Mol Cell Biol. 1990 Dec;10(12):6500–6511. doi: 10.1128/mcb.10.12.6500. [DOI] [PMC free article] [PubMed] [Google Scholar]
  44. Williams F. E., Varanasi U., Trumbly R. J. The CYC8 and TUP1 proteins involved in glucose repression in Saccharomyces cerevisiae are associated in a protein complex. Mol Cell Biol. 1991 Jun;11(6):3307–3316. doi: 10.1128/mcb.11.6.3307. [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Zhang M., Rosenblum-Vos L. S., Lowry C. V., Boakye K. A., Zitomer R. S. A yeast protein with homology to the beta-subunit of G proteins is involved in control of heme-regulated and catabolite-repressed genes. Gene. 1991 Jan 15;97(2):153–161. doi: 10.1016/0378-1119(91)90047-f. [DOI] [PubMed] [Google Scholar]
  46. Zhou Z., Elledge S. J. Isolation of crt mutants constitutive for transcription of the DNA damage inducible gene RNR3 in Saccharomyces cerevisiae. Genetics. 1992 Aug;131(4):851–866. doi: 10.1093/genetics/131.4.851. [DOI] [PMC free article] [PubMed] [Google Scholar]

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