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. 1988 Dec 1;7(12):3975–3982. doi: 10.1002/j.1460-2075.1988.tb03285.x

The Escherichia coli LexA repressor-operator system works in mammalian cells.

G M Smith 1, K A Mileham 1, S E Cooke 1, S J Woolston 1, H K George 1, A D Charles 1, W J Brammar 1
PMCID: PMC454999  PMID: 3208758

Abstract

We have demonstrated the use of the Escherichia coli LexA repressor-operator system to down-regulate gene expression in mouse cells. The LexA gene was placed downstream of the RSVLTR promoter with polyadenylation and splice signals from SV40. This expression unit was introduced into mouse Ltk- cells by calcium phosphate transfection and stable transfectants selected which express LexA protein. We have used the bacterial chloramphenicol acetyltransferase gene (CAT) as our reporter gene. Transcription of this gene was driven by the HSV tk promoter, into which we have introduced one or two synthetic LexA operator sequences in various positions throughout the promoter. Necessary 3' signals were from the HSV tk gene. Repression by LexA was assessed by comparing the transient expression of tkCAT target constructs, containing LexA operator sequences in the promoter, in cells expressing LexA protein with that in control cells not expressing the repressor. We have observed up to 10-fold repression of CAT expression in LexA+ cells from promoters containing LexA operator sequences.

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Selected References

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

  1. Anderson J. E., Ptashne M., Harrison S. C. A phage repressor-operator complex at 7 A resolution. Nature. 1985 Aug 15;316(6029):596–601. doi: 10.1038/316596a0. [DOI] [PubMed] [Google Scholar]
  2. Anderson J. E., Ptashne M., Harrison S. C. Structure of the repressor-operator complex of bacteriophage 434. 1987 Apr 30-May 6Nature. 326(6116):846–852. doi: 10.1038/326846a0. [DOI] [PubMed] [Google Scholar]
  3. Benoist C., Chambon P. In vivo sequence requirements of the SV40 early promotor region. Nature. 1981 Mar 26;290(5804):304–310. doi: 10.1038/290304a0. [DOI] [PubMed] [Google Scholar]
  4. Benson N., Sugiono P., Bass S., Mendelman L. V., Youderian P. General selection for specific DNA-binding activities. Genetics. 1986 Sep;114(1):1–14. doi: 10.1093/genetics/114.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Brent R., Ptashne M. A bacterial repressor protein or a yeast transcriptional terminator can block upstream activation of a yeast gene. Nature. 1984 Dec 13;312(5995):612–615. doi: 10.1038/312612a0. [DOI] [PubMed] [Google Scholar]
  6. Brent R., Ptashne M. A eukaryotic transcriptional activator bearing the DNA specificity of a prokaryotic repressor. Cell. 1985 Dec;43(3 Pt 2):729–736. doi: 10.1016/0092-8674(85)90246-6. [DOI] [PubMed] [Google Scholar]
  7. Brown M., Figge J., Hansen U., Wright C., Jeang K. T., Khoury G., Livingston D. M., Roberts T. M. lac repressor can regulate expression from a hybrid SV40 early promoter containing a lac operator in animal cells. Cell. 1987 Jun 5;49(5):603–612. doi: 10.1016/0092-8674(87)90536-8. [DOI] [PubMed] [Google Scholar]
  8. Coen D. M., Weinheimer S. P., McKnight S. L. A genetic approach to promoter recognition during trans induction of viral gene expression. Science. 1986 Oct 3;234(4772):53–59. doi: 10.1126/science.3018926. [DOI] [PubMed] [Google Scholar]
  9. Cohen R. S., Meselson M. Periodic interactions of heat shock transcriptional elements. Nature. 1988 Apr 28;332(6167):856–858. doi: 10.1038/332856a0. [DOI] [PubMed] [Google Scholar]
  10. Dierks P., van Ooyen A., Cochran M. D., Dobkin C., Reiser J., Weissmann C. Three regions upstream from the cap site are required for efficient and accurate transcription of the rabbit beta-globin gene in mouse 3T6 cells. Cell. 1983 Mar;32(3):695–706. doi: 10.1016/0092-8674(83)90055-7. [DOI] [PubMed] [Google Scholar]
  11. Figge J., Wright C., Collins C. J., Roberts T. M., Livingston D. M. Stringent regulation of stably integrated chloramphenicol acetyl transferase genes by E. coli lac repressor in monkey cells. Cell. 1988 Mar 11;52(5):713–722. doi: 10.1016/0092-8674(88)90409-6. [DOI] [PubMed] [Google Scholar]
  12. Graves B. J., Johnson P. F., McKnight S. L. Homologous recognition of a promoter domain common to the MSV LTR and the HSV tk gene. Cell. 1986 Feb 28;44(4):565–576. doi: 10.1016/0092-8674(86)90266-7. [DOI] [PubMed] [Google Scholar]
  13. Hu M. C., Davidson N. The inducible lac operator-repressor system is functional in mammalian cells. Cell. 1987 Feb 27;48(4):555–566. doi: 10.1016/0092-8674(87)90234-0. [DOI] [PubMed] [Google Scholar]
  14. LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
  15. Lang J. C., Spandidos D. A., Wilkie N. M. Transcriptional regulation of a herpes simplex virus immediate early gene is mediated through an enhancer-type sequence. EMBO J. 1984 Feb;3(2):389–395. doi: 10.1002/j.1460-2075.1984.tb01817.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. McKnight S. L. Constitutive transcriptional control signals of the herpes simplex virus tk gene. Cold Spring Harb Symp Quant Biol. 1983;47(Pt 2):945–958. doi: 10.1101/sqb.1983.047.01.108. [DOI] [PubMed] [Google Scholar]
  17. McKnight S. L. Functional relationships between transcriptional control signals of the thymidine kinase gene of herpes simplex virus. Cell. 1982 Dec;31(2 Pt 1):355–365. doi: 10.1016/0092-8674(82)90129-5. [DOI] [PubMed] [Google Scholar]
  18. McKnight S. L., Kingsbury R. Transcriptional control signals of a eukaryotic protein-coding gene. Science. 1982 Jul 23;217(4557):316–324. doi: 10.1126/science.6283634. [DOI] [PubMed] [Google Scholar]
  19. Reeves R., Gorman C. M., Howard B. Minichromosome assembly of non-integrated plasmid DNA transfected into mammalian cells. Nucleic Acids Res. 1985 May 24;13(10):3599–3615. doi: 10.1093/nar/13.10.3599. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Riggs A. D., Suzuki H., Bourgeois S. Lac repressor-operator interaction. I. Equilibrium studies. J Mol Biol. 1970 Feb 28;48(1):67–83. doi: 10.1016/0022-2836(70)90219-6. [DOI] [PubMed] [Google Scholar]
  21. Schevitz R. W., Otwinowski Z., Joachimiak A., Lawson C. L., Sigler P. B. The three-dimensional structure of trp repressor. 1985 Oct 31-Nov 6Nature. 317(6040):782–786. doi: 10.1038/317782a0. [DOI] [PubMed] [Google Scholar]
  22. Sleigh M. J. A nonchromatographic assay for expression of the chloramphenicol acetyltransferase gene in eucaryotic cells. Anal Biochem. 1986 Jul;156(1):251–256. doi: 10.1016/0003-2697(86)90180-6. [DOI] [PubMed] [Google Scholar]
  23. Takahashi K., Vigneron M., Matthes H., Wildeman A., Zenke M., Chambon P. Requirement of stereospecific alignments for initiation from the simian virus 40 early promoter. Nature. 1986 Jan 9;319(6049):121–126. doi: 10.1038/319121a0. [DOI] [PubMed] [Google Scholar]
  24. Wharton R. P., Brown E. L., Ptashne M. Substituting an alpha-helix switches the sequence-specific DNA interactions of a repressor. Cell. 1984 Sep;38(2):361–369. doi: 10.1016/0092-8674(84)90491-4. [DOI] [PubMed] [Google Scholar]
  25. Wharton R. P., Ptashne M. Changing the binding specificity of a repressor by redesigning an alpha-helix. Nature. 1985 Aug 15;316(6029):601–605. doi: 10.1038/316601a0. [DOI] [PubMed] [Google Scholar]
  26. Youderian P., Vershon A., Bouvier S., Sauer R. T., Susskind M. M. Changing the DNA-binding specificity of a repressor. Cell. 1983 Dec;35(3 Pt 2):777–783. doi: 10.1016/0092-8674(83)90110-1. [DOI] [PubMed] [Google Scholar]
  27. Zhang R. G., Joachimiak A., Lawson C. L., Schevitz R. W., Otwinowski Z., Sigler P. B. The crystal structure of trp aporepressor at 1.8 A shows how binding tryptophan enhances DNA affinity. Nature. 1987 Jun 18;327(6123):591–597. doi: 10.1038/327591a0. [DOI] [PubMed] [Google Scholar]

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