Skip to main content
NCBI home page
Plant Physiology logoLink to Plant Physiology
. 1982 Jan;69(1):263–267. doi: 10.1104/pp.69.1.263

On the Participation of Phosphoribulokinase in the Light Regulation of CO2 Fixation 1

U Ingo Flügge 1, Mark Stitt 1, Martha Freisl 1, Hans W Heldt 1
PMCID: PMC426186  PMID: 16662172

Abstract

CO2 fixation by a suspension of isolated spinach chloroplasts was terminated by turning off the light, and changes of metabolite levels in the chloroplast stroma and the surrounding medium were assayed. Whereas CO2 fixation comes to a total stop within 15 seconds, a conversion of triose phosphates to heptose, hexose, and pentose monophosphates is found to occur for 1 to 2 minutes afterwards. It seems from these data that an inactivation of fructose and sedoheptulose bisphosphatases proceeds with a lag period. In contrast, the conversion of pentose monophosphates to ribulose 1,5-bisphosphate is inhibited immediately after the stop of illumination. As the stromal level of freely available ATP was not depleted under this condition, these data demonstrate that ribulose 5-phosphate kinase was very rapidly inactivated after darkening of the chloroplasts. Essentially, the same effect is also observed when CO2 fixation is partially inhibited by addition of moderate concentrations of m-chlorocarbonyl phenylhydrazone, partially uncoupling photophosphorylation. It appears from these results, that the activity of ribulose 5-phosphate kinase is not only regulated by light through the mediation of reduced carriers like thioredoxin but also by alternative parameters, e.g. stromal metabolite levels.

Full text

PDF
263

Selected References

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

  1. Anderson L. E. Regulation of pea leaf ribulose-5-phosphate kinase activity. Biochim Biophys Acta. 1973 Oct 10;321(2):484–488. doi: 10.1016/0005-2744(73)90190-3. [DOI] [PubMed] [Google Scholar]
  2. Fliege R., Flügge U. I., Werdan K., Heldt H. W. Specific transport of inorganic phosphate, 3-phosphoglycerate and triosephosphates across the inner membrane of the envelope in spinach chloroplasts. Biochim Biophys Acta. 1978 May 10;502(2):232–247. doi: 10.1016/0005-2728(78)90045-2. [DOI] [PubMed] [Google Scholar]
  3. Giersch C., Heber U., Kobayashi Y., Inoue Y., Shibata K., Heldt H. W. Energy charge, phosphorylation potential and proton motive force in chloroplasts. Biochim Biophys Acta. 1980 Mar 7;590(1):59–73. doi: 10.1016/0005-2728(80)90146-2. [DOI] [PubMed] [Google Scholar]
  4. Heldt W. H., Werdan K., Milovancev M., Geller G. Alkalization of the chloroplast stroma caused by light-dependent proton flux into the thylakoid space. Biochim Biophys Acta. 1973 Aug 31;314(2):224–241. doi: 10.1016/0005-2728(73)90137-0. [DOI] [PubMed] [Google Scholar]
  5. Kaiser W. M., Bassham J. A. Light-Dark Regulation of Starch Metabolism in Chloroplasts: I. Levels of Metabolites in Chloroplasts and Medium during Light-Dark Transition. Plant Physiol. 1979 Jan;63(1):105–108. doi: 10.1104/pp.63.1.105. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Lilley R. M., Chon C. J., Mosbach A., Heldt H. W. The distribution of metabolites between spinach chloroplasts and medium during photosynthesis in vitro. Biochim Biophys Acta. 1977 May 11;460(2):259–272. doi: 10.1016/0005-2728(77)90212-2. [DOI] [PubMed] [Google Scholar]
  7. Lilley R. M., Walker D. A. The reduction of 3-phosphoglycerate by reconstituted chloroplasts and by chloroplast extracts. Biochim Biophys Acta. 1974 Dec 19;368(3):269–278. doi: 10.1016/0005-2728(74)90174-1. [DOI] [PubMed] [Google Scholar]
  8. Portis A. R., Jr, Chon C. J., Mosbach A., Heldt H. W. Fructose-and sedoheptulosebisphosphatase. The sites of a possible control of CO2 fixation by lightdependent changes of the stromal Mg2+ concentration. Biochim Biophys Acta. 1977 Aug 10;461(2):313–325. doi: 10.1016/0005-2728(77)90181-5. [DOI] [PubMed] [Google Scholar]
  9. Purczeld P., Chon C. J., Portis A. R., Jr, Heldt H. W., Heber U. The mechanism of the control of carbon fixation by the pH in the chloroplast stroma. Studies with nitrite-mediated proton transfer across the envelope. Biochim Biophys Acta. 1978 Mar 13;501(3):488–498. doi: 10.1016/0005-2728(78)90116-0. [DOI] [PubMed] [Google Scholar]
  10. Wirtz W., Stitt M., Heldt H. W. Enzymic determination of metabolites in the subcellular compartments of spinach protoplasts. Plant Physiol. 1980 Jul;66(1):187–193. doi: 10.1104/pp.66.1.187. [DOI] [PMC free article] [PubMed] [Google Scholar]

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

RESOURCES