Skip to main content
NCBI home page
Plant Physiology logoLink to Plant Physiology
. 1994 Jul;105(3):955–964. doi: 10.1104/pp.105.3.955

Characterization of a chloroplast inner envelope K+ channel.

F Mi 1, J S Peters 1, G A Berkowitz 1
PMCID: PMC160746  PMID: 8058841

Abstract

A K(+)-conducting protein of the chloroplast inner envelope was characterized as a K+ channel. Studies of this transport protein in the native membrane documented its sensitivity to K+ channel blockers. Further studies of native membranes demonstrated a sensitivity of K+ conductance to divalent cations such as Mg2+, which modulate ion conduction through interaction with negative surface charges on the inner-envelope membrane. Purified chloroplast inner-envelope vesicles were fused into an artificial planar lipid bilayer to facilitate recording of single-channel K+ currents. These single-channel K+ currents had a slope conductance of 160 picosiemens. Antibodies generated against the conserved amino acid sequence that serves as a selectivity filter in the pore of K+ channels immunoreacted with a 62-kD polypeptide derived from the chloroplast inner envelope. This polypeptide was fractionated using density gradient centrifugation. Comigration of this immunoreactive polypeptide and K+ channel activity in sucrose density gradients further suggested that this polypeptide is the protein facilitating K+ conductance across the chloroplast inner envelope.

Full Text

The Full Text of this article is available as a PDF (2.0 MB).

Selected References

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

  1. Bara M., Guiet-Bara A., Durlach J. A qualitative theory of the screening-binding effects of magnesium salts on epithelial cell membranes: a new hypothesis. Magnes Res. 1989 Dec;2(4):243–248. [PubMed] [Google Scholar]
  2. Barbas J. A., Rubio N., Pedroso E., Pongs O., Ferrús A. Antibodies against Drosophila potassium channels identify membrane proteins across species. Brain Res Mol Brain Res. 1989 Mar;5(2):171–176. doi: 10.1016/0169-328x(89)90008-9. [DOI] [PubMed] [Google Scholar]
  3. Berkowitz G. A., Peters J. S. Chloroplast Inner-Envelope ATPase Acts as a Primary H+ Pump. Plant Physiol. 1993 May;102(1):261–267. doi: 10.1104/pp.102.1.261. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Berkowitz G. A., Wu W. Magnesium, potassium flux and photosynthesis. Magnes Res. 1993 Sep;6(3):257–265. [PubMed] [Google Scholar]
  5. Bowie J. U., Reidhaar-Olson J. F., Lim W. A., Sauer R. T. Deciphering the message in protein sequences: tolerance to amino acid substitutions. Science. 1990 Mar 16;247(4948):1306–1310. doi: 10.1126/science.2315699. [DOI] [PubMed] [Google Scholar]
  6. Fermini B., Nathan R. D. Sialic acid and the surface charge associated with hyperpolarization-activated, inward rectifying channels. J Membr Biol. 1990 Mar;114(1):61–69. doi: 10.1007/BF01869385. [DOI] [PubMed] [Google Scholar]
  7. Gentry L. E., Rohrschneider L. R., Casnellie J. E., Krebs E. G. Antibodies to a defined region of pp60src neutralize the tyrosine-specific kinase activity. J Biol Chem. 1983 Sep 25;258(18):11219–11228. [PubMed] [Google Scholar]
  8. Gupta A. S., Berkowitz G. A. Development and use of chlorotetracycline fluorescence as a measurement assay of chloroplast envelope-bound mg. Plant Physiol. 1989 Mar;89(3):753–761. doi: 10.1104/pp.89.3.753. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Hausdorff S. F., Goldstein S. A., Rushin E. E., Miller C. Functional characterization of a minimal K+ channel expressed from a synthetic gene. Biochemistry. 1991 Apr 2;30(13):3341–3346. doi: 10.1021/bi00227a025. [DOI] [PubMed] [Google Scholar]
  10. Hille B., Woodhull A. M., Shapiro B. I. Negative surface charge near sodium channels of nerve: divalent ions, monovalent ions, and pH. Philos Trans R Soc Lond B Biol Sci. 1975 Jun 10;270(908):301–318. doi: 10.1098/rstb.1975.0011. [DOI] [PubMed] [Google Scholar]
  11. Houghten R. A. General method for the rapid solid-phase synthesis of large numbers of peptides: specificity of antigen-antibody interaction at the level of individual amino acids. Proc Natl Acad Sci U S A. 1985 Aug;82(15):5131–5135. doi: 10.1073/pnas.82.15.5131. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Kumpf R. A., Dougherty D. A. A mechanism for ion selectivity in potassium channels: computational studies of cation-pi interactions. Science. 1993 Sep 24;261(5129):1708–1710. doi: 10.1126/science.8378771. [DOI] [PubMed] [Google Scholar]
  13. Maury W. J., Huber S. C., Moreland D. E. Effects of Magnesium on Intact Chloroplasts : II. CATION SPECIFICITY AND INVOLVEMENT OF THE ENVELOPE ATPase IN (SODIUM) POTASSIUM/PROTON EXCHANGE ACROSS THE ENVELOPE. Plant Physiol. 1981 Dec;68(6):1257–1263. doi: 10.1104/pp.68.6.1257. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. McKinley D., Meissner G. Evidence for a K+, Na+ permeable channel in sarcoplasmic reticulum. J Membr Biol. 1978 Dec 15;44(2):159–186. doi: 10.1007/BF01976037. [DOI] [PubMed] [Google Scholar]
  15. Miller C. Open-state substructure of single chloride channels from Torpedo electroplax. Philos Trans R Soc Lond B Biol Sci. 1982 Dec 1;299(1097):401–411. doi: 10.1098/rstb.1982.0140. [DOI] [PubMed] [Google Scholar]
  16. Tester M., Blatt M. R. Direct measurement of k channels in thylakoid membranes by incorporation of vesicles into planar lipid bilayers. Plant Physiol. 1989 Sep;91(1):249–252. doi: 10.1104/pp.91.1.249. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Trimmer J. S. Immunological identification and characterization of a delayed rectifier K+ channel polypeptide in rat brain. Proc Natl Acad Sci U S A. 1991 Dec 1;88(23):10764–10768. doi: 10.1073/pnas.88.23.10764. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Tsao J. L., Lin X., Lackland H., Tous G., Wu Y. L., Stein S. Internally standardized amino acid analysis for determining peptide/carrier protein coupling ratio. Anal Biochem. 1991 Aug 15;197(1):137–142. doi: 10.1016/0003-2697(91)90369-5. [DOI] [PubMed] [Google Scholar]
  19. Wang X., Berkowitz G. A., Peters J. S. K+-conducting ion channel of the chloroplast inner envelope: functional reconstitution into liposomes. Proc Natl Acad Sci U S A. 1993 Jun 1;90(11):4981–4985. doi: 10.1073/pnas.90.11.4981. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Werner-Washburne M., Cline K., Keegstra K. Analysis of pea chloroplast inner and outer envelope membrane proteins by two-dimensional gel electrophoresis and their comparison with stromal proteins. Plant Physiol. 1983 Nov;73(3):569–575. doi: 10.1104/pp.73.3.569. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Wu W., Berkowitz G. A. Stromal pH and Photosynthesis Are Affected by Electroneutral K and H Exchange through Chloroplast Envelope Ion Channels. Plant Physiol. 1992 Feb;98(2):666–672. doi: 10.1104/pp.98.2.666. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Wu W., Peters J., Berkowitz G. A. Surface Charge-Mediated Effects of Mg on K Flux across the Chloroplast Envelope Are Associated with Regulation of Stromal pH and Photosynthesis. Plant Physiol. 1991 Oct;97(2):580–587. doi: 10.1104/pp.97.2.580. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Plant Physiology are provided here courtesy of Oxford University Press

RESOURCES