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Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1989 Feb;86(4):1153–1157. doi: 10.1073/pnas.86.4.1153

In vitro reconstitution of osmoregulated expression of proU of Escherichia coli.

R M Ramirez 1, W S Prince 1, E Bremer 1, M Villarejo 1
PMCID: PMC286644  PMID: 2645575

Abstract

Osmoregulated expression of proU has been reconstituted in a cell-free system. proU encodes an osmotically inducible, high-affinity transport system for the osmoprotectant glycine betaine in Escherichia coli. Previously, a proU-lacZ fusion gene had been cloned, resulting in plasmid pOS3. In vivo osmoregulation of this extrachromosomal proU-lacZ fusion gene at low copy number showed that the plasmid-encoded fusion contained all the necessary sequences in cis for correctly receiving osmoregulatory signals during induction by osmotic stress and repression by glycine betaine. Using a cell-free (S-30) extract, plasmid pOS3 was then used to program protein synthesis in vitro. The ionic compound potassium glutamate specifically stimulated proU-lacZ expression in a concentration-dependent manner. Potassium acetate also induced some proU expression, but other salts were ineffective, thereby ruling out ionic strength as the stimulatory signal. High concentrations of sucrose, trehalose, or glycine betaine did not induce proU expression in vitro either, eliminating osmolarity per se as the stimulus. Reconstitution in a cell-free system rules out osmoregulatory mechanisms that depend on turgor, trans-membrane signaling, or trans-acting regulators synthesized after osmotic upshock.

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Selected References

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  1. Alphen W. V., Lugtenberg B. Influence of osmolarity of the growth medium on the outer membrane protein pattern of Escherichia coli. J Bacteriol. 1977 Aug;131(2):623–630. doi: 10.1128/jb.131.2.623-630.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bakker E. P., Booth I. R., Dinnbier U., Epstein W., Gajewska A. Evidence for multiple K+ export systems in Escherichia coli. J Bacteriol. 1987 Aug;169(8):3743–3749. doi: 10.1128/jb.169.8.3743-3749.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Barron A., Jung J. U., Villarejo M. Purification and characterization of a glycine betaine binding protein from Escherichia coli. J Biol Chem. 1987 Aug 25;262(24):11841–11846. [PubMed] [Google Scholar]
  4. Barron A., May G., Bremer E., Villarejo M. Regulation of envelope protein composition during adaptation to osmotic stress in Escherichia coli. J Bacteriol. 1986 Aug;167(2):433–438. doi: 10.1128/jb.167.2.433-438.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Bloom M., Skelly S., VanBogelen R., Neidhardt F., Brot N., Weissbach H. In vitro effect of the Escherichia coli heat shock regulatory protein on expression of heat shock genes. J Bacteriol. 1986 May;166(2):380–384. doi: 10.1128/jb.166.2.380-384.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Cairney J., Booth I. R., Higgins C. F. Osmoregulation of gene expression in Salmonella typhimurium: proU encodes an osmotically induced betaine transport system. J Bacteriol. 1985 Dec;164(3):1224–1232. doi: 10.1128/jb.164.3.1224-1232.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Cairney J., Booth I. R., Higgins C. F. Salmonella typhimurium proP gene encodes a transport system for the osmoprotectant betaine. J Bacteriol. 1985 Dec;164(3):1218–1223. doi: 10.1128/jb.164.3.1218-1223.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Comeau D. E., Ikenaka K., Tsung K. L., Inouye M. Primary characterization of the protein products of the Escherichia coli ompB locus: structure and regulation of synthesis of the OmpR and EnvZ proteins. J Bacteriol. 1985 Nov;164(2):578–584. doi: 10.1128/jb.164.2.578-584.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Druger-Liotta J., Prange V. J., Overdier D. G., Csonka L. N. Selection of mutations that alter the osmotic control of transcription of the Salmonella typhimurium proU operon. J Bacteriol. 1987 Jun;169(6):2449–2459. doi: 10.1128/jb.169.6.2449-2459.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Faatz E., Middendorf A., Bremer E. Cloned structural genes for the osmotically regulated binding-protein-dependent glycine betaine transport system (ProU) of Escherichia coli K-12. Mol Microbiol. 1988 Mar;2(2):265–279. doi: 10.1111/j.1365-2958.1988.tb00028.x. [DOI] [PubMed] [Google Scholar]
  11. Giaever H. M., Styrvold O. B., Kaasen I., Strøm A. R. Biochemical and genetic characterization of osmoregulatory trehalose synthesis in Escherichia coli. J Bacteriol. 1988 Jun;170(6):2841–2849. doi: 10.1128/jb.170.6.2841-2849.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Grothe S., Krogsrud R. L., McClellan D. J., Milner J. L., Wood J. M. Proline transport and osmotic stress response in Escherichia coli K-12. J Bacteriol. 1986 Apr;166(1):253–259. doi: 10.1128/jb.166.1.253-259.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Gutierrez C., Barondess J., Manoil C., Beckwith J. The use of transposon TnphoA to detect genes for cell envelope proteins subject to a common regulatory stimulus. Analysis of osmotically regulated genes in Escherichia coli. J Mol Biol. 1987 May 20;195(2):289–297. doi: 10.1016/0022-2836(87)90650-4. [DOI] [PubMed] [Google Scholar]
  14. Higgins C. F., Dorman C. J., Stirling D. A., Waddell L., Booth I. R., May G., Bremer E. A physiological role for DNA supercoiling in the osmotic regulation of gene expression in S. typhimurium and E. coli. Cell. 1988 Feb 26;52(4):569–584. doi: 10.1016/0092-8674(88)90470-9. [DOI] [PubMed] [Google Scholar]
  15. 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]
  16. Laimins L. A., Rhoads D. B., Epstein W. Osmotic control of kdp operon expression in Escherichia coli. Proc Natl Acad Sci U S A. 1981 Jan;78(1):464–468. doi: 10.1073/pnas.78.1.464. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Landfald B., Strøm A. R. Choline-glycine betaine pathway confers a high level of osmotic tolerance in Escherichia coli. J Bacteriol. 1986 Mar;165(3):849–855. doi: 10.1128/jb.165.3.849-855.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Leirmo S., Harrison C., Cayley D. S., Burgess R. R., Record M. T., Jr Replacement of potassium chloride by potassium glutamate dramatically enhances protein-DNA interactions in vitro. Biochemistry. 1987 Apr 21;26(8):2095–2101. doi: 10.1021/bi00382a006. [DOI] [PubMed] [Google Scholar]
  19. Lopilato J., Bortner S., Beckwith J. Mutations in a new chromosomal gene of Escherichia coli K-12, pcnB, reduce plasmid copy number of pBR322 and its derivatives. Mol Gen Genet. 1986 Nov;205(2):285–290. doi: 10.1007/BF00430440. [DOI] [PubMed] [Google Scholar]
  20. May G., Faatz E., Villarejo M., Bremer E. Binding protein dependent transport of glycine betaine and its osmotic regulation in Escherichia coli K12. Mol Gen Genet. 1986 Nov;205(2):225–233. doi: 10.1007/BF00430432. [DOI] [PubMed] [Google Scholar]
  21. Measures J. C. Role of amino acids in osmoregulation of non-halophilic bacteria. Nature. 1975 Oct 2;257(5525):398–400. doi: 10.1038/257398a0. [DOI] [PubMed] [Google Scholar]
  22. Norioka S., Ramakrishnan G., Ikenaka K., Inouye M. Interaction of a transcriptional activator, OmpR, with reciprocally osmoregulated genes, ompF and ompC, of Escherichia coli. J Biol Chem. 1986 Dec 25;261(36):17113–17119. [PubMed] [Google Scholar]
  23. Perroud B., Le Rudulier D. Glycine betaine transport in Escherichia coli: osmotic modulation. J Bacteriol. 1985 Jan;161(1):393–401. doi: 10.1128/jb.161.1.393-401.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Rhoads D. B., Waters F. B., Epstein W. Cation transport in Escherichia coli. VIII. Potassium transport mutants. J Gen Physiol. 1976 Mar;67(3):325–341. doi: 10.1085/jgp.67.3.325. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Richey B., Cayley D. S., Mossing M. C., Kolka C., Anderson C. F., Farrar T. C., Record M. T., Jr Variability of the intracellular ionic environment of Escherichia coli. Differences between in vitro and in vivo effects of ion concentrations on protein-DNA interactions and gene expression. J Biol Chem. 1987 May 25;262(15):7157–7164. [PubMed] [Google Scholar]
  26. Ronson C. W., Nixon B. T., Ausubel F. M. Conserved domains in bacterial regulatory proteins that respond to environmental stimuli. Cell. 1987 Jun 5;49(5):579–581. doi: 10.1016/0092-8674(87)90530-7. [DOI] [PubMed] [Google Scholar]
  27. Sutherland L., Cairney J., Elmore M. J., Booth I. R., Higgins C. F. Osmotic regulation of transcription: induction of the proU betaine transport gene is dependent on accumulation of intracellular potassium. J Bacteriol. 1986 Nov;168(2):805–814. doi: 10.1128/jb.168.2.805-814.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Twigg A. J., Sherratt D. Trans-complementable copy-number mutants of plasmid ColE1. Nature. 1980 Jan 10;283(5743):216–218. doi: 10.1038/283216a0. [DOI] [PubMed] [Google Scholar]
  29. Wanner B. L., Sarthy A., Beckwith J. Escherichia coli pleiotropic mutant that reduces amounts of several periplasmic and outer membrane proteins. J Bacteriol. 1979 Oct;140(1):229–239. doi: 10.1128/jb.140.1.229-239.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]

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