Abstract
We studied the changes in various cell functions during the shift to alkaline extracellular pH in wild-type Escherichia coli and in strain DZ3, a mutant defective in pH homeostasis. A rapid increase in membrane potential (delta psi) was detected in both the wild type and the mutant immediately upon the shift, when both cell types failed to control intracellular pH. Upon reestablishment of intracellular pH - extracellular pH and growth in the wild type, delta psi decreased to a new steady-state value. The electrochemical proton gradient (delta muH+) was similar in magnitude to that observed before the pH shift. In the mutant DZ3, delta psi remained elevated, and even though delta muH+ was higher than in the wild type, growth was impaired. Cessation of growth in the mutant is not a result of cell death. Hence, the mutant affords an interesting system to explore the intracellular-pH-sensitive steps that arrest growth without affecting viability. In addition to delta muH+, we measured respiration rates, protein synthesis, cell viability, induction of beta-galactosidase, DNA synthesis, and cell elongation upon failure of pH homeostasis. Cell division was the only function arrested after the shift in extracellular pH. The cells formed long chains with no increase in colony-forming capacity.
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- Ahmed S., Booth I. R. The effect of beta-galactosides on the protonmotive force and growth of Escherichia coli. J Gen Microbiol. 1983 Aug;129(8):2521–2529. doi: 10.1099/00221287-129-8-2521. [DOI] [PubMed] [Google Scholar]
- Barton J. K., den Hollander J. A., Lee T. M., MacLaughlin A., Shulman R. G. Measurement of the internal pH of yeast spores by 31P nuclear magnetic resonance. Proc Natl Acad Sci U S A. 1980 May;77(5):2470–2473. doi: 10.1073/pnas.77.5.2470. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brey R. N., Beck J. C., Rosen B. P. Cation/proton antiport systems in Escherichia coli. Biochem Biophys Res Commun. 1978 Aug 29;83(4):1588–1594. doi: 10.1016/0006-291x(78)91403-1. [DOI] [PubMed] [Google Scholar]
- Brey R. N., Rosen B. P., Sorensen E. N. Cation/proton antiport systems in Escherichia coli. Properties of the potassium/proton antiporter. J Biol Chem. 1980 Jan 10;255(1):39–44. [PubMed] [Google Scholar]
- DAVIS B. D., MINGIOLI E. S. Mutants of Escherichia coli requiring methionine or vitamin B12. J Bacteriol. 1950 Jul;60(1):17–28. doi: 10.1128/jb.60.1.17-28.1950. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Harold F. M., Van Brunt J. Circulation of H+ and K+ across the plasma membrane is not obligatory for bacterial growth. Science. 1977 Jul 22;197(4301):372–373. doi: 10.1126/science.69317. [DOI] [PubMed] [Google Scholar]
- Johnson J. D., Epel D. Intracellular pH and activation of sea urchin eggs after fertilisation. Nature. 1976 Aug 19;262(5570):661–664. doi: 10.1038/262661a0. [DOI] [PubMed] [Google Scholar]
- Kashket E. R. Stoichiometry of the H+-ATPase of growing and resting, aerobic Escherichia coli. Biochemistry. 1982 Oct 26;21(22):5534–5538. doi: 10.1021/bi00265a024. [DOI] [PubMed] [Google Scholar]
- Krulwich T. A., Mandel K. G., Bornstein R. F., Guffanti A. A. A non-alkalophilic mutant of Bacillus alcalophilus lacks the Na+/H+ antiporter. Biochem Biophys Res Commun. 1979 Nov 14;91(1):58–62. doi: 10.1016/0006-291x(79)90582-5. [DOI] [PubMed] [Google Scholar]
- 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]
- Lanyi J. K. The role of Na+ in transport processes of bacterial membranes. Biochim Biophys Acta. 1979 Dec 20;559(4):377–397. doi: 10.1016/0304-4157(79)90011-x. [DOI] [PubMed] [Google Scholar]
- Mitchell P. The Ninth Sir Hans Krebs Lecture. Compartmentation and communication in living systems. Ligand conduction: a general catalytic principle in chemical, osmotic and chemiosmotic reaction systems. Eur J Biochem. 1979 Mar 15;95(1):1–20. doi: 10.1111/j.1432-1033.1979.tb12934.x. [DOI] [PubMed] [Google Scholar]
- Padan E., Zilberstein D., Rottenberg H. The proton electrochemical gradient in Escherichia coli cells. Eur J Biochem. 1976 Apr 1;63(2):533–541. doi: 10.1111/j.1432-1033.1976.tb10257.x. [DOI] [PubMed] [Google Scholar]
- Padan E., Zilberstein D., Schuldiner S. pH homeostasis in bacteria. Biochim Biophys Acta. 1981 Dec;650(2-3):151–166. doi: 10.1016/0304-4157(81)90004-6. [DOI] [PubMed] [Google Scholar]
- Schuldiner S., Rozengurt E. Na+/H+ antiport in Swiss 3T3 cells: mitogenic stimulation leads to cytoplasmic alkalinization. Proc Natl Acad Sci U S A. 1982 Dec;79(24):7778–7782. doi: 10.1073/pnas.79.24.7778. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Setlow B., Setlow P. Measurements of the pH within dormant and germinated bacterial spores. Proc Natl Acad Sci U S A. 1980 May;77(5):2474–2476. doi: 10.1073/pnas.77.5.2474. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Slonczewski J. L., Rosen B. P., Alger J. R., Macnab R. M. pH homeostasis in Escherichia coli: measurement by 31P nuclear magnetic resonance of methylphosphonate and phosphate. Proc Natl Acad Sci U S A. 1981 Oct;78(10):6271–6275. doi: 10.1073/pnas.78.10.6271. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zilberstein D., Agmon V., Schuldiner S., Padan E. The sodium/proton antiporter is part of the pH homeostasis mechanism in Escherichia coli. J Biol Chem. 1982 Apr 10;257(7):3687–3691. [PubMed] [Google Scholar]
- Zilberstein D., Padan E., Schuldiner S. A single locus in Escherichia coli governs growth in alkaline pH and on carbon sources whose transport is sodium dependent. FEBS Lett. 1980 Jul 28;116(2):177–180. doi: 10.1016/0014-5793(80)80637-5. [DOI] [PubMed] [Google Scholar]
- Zilberstein D., Schuldiner S., Padan E. Proton electrochemical gradient in Escherichia coli cells and its relation to active transport of lactose. Biochemistry. 1979 Feb 20;18(4):669–673. doi: 10.1021/bi00571a018. [DOI] [PubMed] [Google Scholar]