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. 1979 Jul;64(1):139–143. doi: 10.1104/pp.64.1.139

Salt-induced Inhibition of Phosphate Transport and Release of Membrane Proteins from Barley Roots

Eugene V Maas 1, Gen Ogata 1, Martin H Finkel 1
PMCID: PMC543040  PMID: 16660902

Abstract

Osmotic shock with sequential 30-minute treatments in ice-cold saline solutions and H2O released proteins from excised barley roots and inhibited the subsequent uptake of orthophosphate (Pi). The amount of protein released increased sharply at NaCl concentrations above 0.05 molar, approximately the threshold concentration above which Pi uptake was increasingly suppressed. About 60% of the nearly 100 micrograms of protein per gram fresh weight of roots that was eluted in 0.16 molar NaCl treatments apparently had no function in Pi transport, since it was eluted at NaCl concentrations (≤0.05 molar) that did not affect Pi uptake. Although 0.16 molar NaCl completely inhibited Pi uptake, active uptake resumed at about 60% of control rates within 1 to 2 hours. The presence of either puromycin or cycloheximide greatly reduced the recovery of Pi uptake activity after the NaCl treatment. Mannitol and various monovalent and divalent salts at concentrations isosmotic with NaCl also inhibited Pi uptake, but CaCl2 was consistently the least inhibitory. The correlation between the concentration of the osmotic treatments and the simultaneous loss of protein and Pi uptake activity, together with the evidence that uptake recovery requires protein synthesis, support the hypothesis that the proteins eluted are required for active Pi transport.

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Selected References

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

  1. Amar L., Reinhold L. Loss of membrane transport ability in leaf cells and release of protein as a result of osmotic shock. Plant Physiol. 1973 Apr;51(4):620–625. doi: 10.1104/pp.51.4.620. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Boos W. Bacterial transport. Annu Rev Biochem. 1974;43(0):123–146. doi: 10.1146/annurev.bi.43.070174.001011. [DOI] [PubMed] [Google Scholar]
  3. Greenway H. Effects of slowly permeating osmotica on metabolism of vacuolated and nonvacuolated tissues. Plant Physiol. 1970 Aug;46(2):254–258. doi: 10.1104/pp.46.2.254. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Kaback H. R. Transport. Annu Rev Biochem. 1970;39:561–598. doi: 10.1146/annurev.bi.39.070170.003021. [DOI] [PubMed] [Google Scholar]
  5. 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]
  6. Medveczky N., Rosenberg H. The binding and release of phosphate by a protein isolated from Escherichia coli. Biochim Biophys Acta. 1969 Nov 18;192(2):369–371. doi: 10.1016/0304-4165(69)90382-1. [DOI] [PubMed] [Google Scholar]
  7. Nieman R. H., Willis C. Correlation between the Suppression of Glucose and Phosphate Uptake and the Release of Protein from Viable Carrot Root Cells Treated with Monovalent Cations. Plant Physiol. 1971 Sep;48(3):287–293. doi: 10.1104/pp.48.3.287. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Oxender D. L. Membrane transport. Annu Rev Biochem. 1972;41(10):777–814. doi: 10.1146/annurev.bi.41.070172.004021. [DOI] [PubMed] [Google Scholar]
  9. Pardee A. B. Membrane transport proteins. Proteins that appear to be parts of membrane transport systems are being isolated and characterized. Science. 1968 Nov 8;162(3854):632–637. doi: 10.1126/science.162.3854.632. [DOI] [PubMed] [Google Scholar]
  10. Rubinstein B., Mahar P. Effects of Osmotic Shock on Some Membrane-regulated Events of Oat Coleoptile Cells. Plant Physiol. 1977 Mar;59(3):365–368. doi: 10.1104/pp.59.3.365. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Singer S. J., Nicolson G. L. The fluid mosaic model of the structure of cell membranes. Science. 1972 Feb 18;175(4023):720–731. doi: 10.1126/science.175.4023.720. [DOI] [PubMed] [Google Scholar]
  12. Singer S. J. The molecular organization of membranes. Annu Rev Biochem. 1974;43(0):805–833. doi: 10.1146/annurev.bi.43.070174.004105. [DOI] [PubMed] [Google Scholar]
  13. TAUSSKY H. H., SHORR E. A microcolorimetric method for the determination of inorganic phosphorus. J Biol Chem. 1953 Jun;202(2):675–685. [PubMed] [Google Scholar]
  14. Wiley W. R. Tryptophan transport in Neurospora crassa: a tryptophan-binding protein released by cold osmotic shock. J Bacteriol. 1970 Sep;103(3):656–662. doi: 10.1128/jb.103.3.656-662.1970. [DOI] [PMC free article] [PubMed] [Google Scholar]

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