Abstract
An important question concerning the role of carboxyarabinitol 1-phosphate (CA1P) metabolism in the light-dependent regulation of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity is the extent to which CA1P is bound to Rubisco in vivo. We report here the development of an extraction procedure using ammonium sulfate that stabilizes CA1P bound to Rubisco. This procedure exploits the ability of sulfate to bind at the catalytic site of Rubisco and to competitively balance the binding and release of CA1P from Rubisco. In darkened bean leaves about 75% of the Rubisco catalytic sites were found to be bound with CA1P. This confirms previous indirect estimates from gas exchange measurements. We have used this extraction procedure to examine CA1P-Rubisco interactions in bean during a natural transition from darkness to light. With increasing light intensity following sunrise, CA1P degradation proceeded in two distinct phases: first, a majority of the unbound CA1P pool was degraded at very low light levels ([less than or equal to]30 [mu]mol quanta m-2 s-1); second, CA1P initially bound to Rubisco was then degraded at increasing light levels (>30 [mu]mol quanta m-2 s-1). These results indicate that there is a low-fluence activation of CA1P phosphatase that can occur prior to CA1P release by Rubisco activase. This activation may be mediated by NADPH. During sunrise in bean, the level of the catalytically competent form of Rubisco was regulated by CA1P metabolism.
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- Berry J. A., Lorimer G. H., Pierce J., Seemann J. R., Meek J., Freas S. Isolation, identification, and synthesis of 2-carboxyarabinitol 1-phosphate, a diurnal regulator of ribulose-bisphosphate carboxylase activity. Proc Natl Acad Sci U S A. 1987 Feb;84(3):734–738. doi: 10.1073/pnas.84.3.734. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Evans J. R., Seemann J. R. Differences between Wheat Genotypes in Specific Activity of Ribulose-1,5-bisphosphate Carboxylase and the Relationship to Photosynthesis. Plant Physiol. 1984 Apr;74(4):759–765. doi: 10.1104/pp.74.4.759. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gutteridge S., Reddy G. S., Lorimer G. The synthesis and purification of 2'-carboxy-D-arabinitol 1-phosphate, a natural inhibitor of ribulose 1,5-bisphosphate carboxylase, investigated by 31P n.m.r. Biochem J. 1989 Jun 15;260(3):711–716. doi: 10.1042/bj2600711. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Holbrook G. P., Bowes G., Salvucci M. E. Degradation of 2-carboxyarabinitol 1-phosphate by a specific chloroplast phosphatase. Plant Physiol. 1989 Jun;90(2):673–678. doi: 10.1104/pp.90.2.673. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kobza J., Seemann J. R. Mechanisms for light-dependent regulation of ribulose-1,5-bisphosphate carboxylase activity and photosynthesis in intact leaves. Proc Natl Acad Sci U S A. 1988 Jun;85(11):3815–3819. doi: 10.1073/pnas.85.11.3815. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McCurry S. D., Pierce J., Tolbert N. E., Orme-Johnson W. H. On the mechanism of effector-mediated activation of ribulose bisphosphate carboxylase/oxygenase. J Biol Chem. 1981 Jul 10;256(13):6623–6628. [PubMed] [Google Scholar]
- Moore B. D., Seemann J. R. Metabolism of 2'-carboxyarabinitol in leaves. Plant Physiol. 1992 Aug;99(4):1551–1555. doi: 10.1104/pp.99.4.1551. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sage R. F., Sharkey T. D., Seemann J. R. Regulation of Ribulose-1,5-Bisphosphate Carboxylase Activity in Response to Light Intensity and CO(2) in the C(3) Annuals Chenopodium album L. and Phaseolus vulgaris L. Plant Physiol. 1990 Dec;94(4):1735–1742. doi: 10.1104/pp.94.4.1735. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Salvucci M. E., Anderson J. C. Factors affecting the activation state and the level of total activity of ribulose bisphosphate carboxylase in tobacco protoplasts. Plant Physiol. 1987 Sep;85(1):66–71. doi: 10.1104/pp.85.1.66. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Salvucci M. E., Holbrook G. P. Purification and Properties of 2-Carboxy-d-Arabinitol 1-Phosphatase. Plant Physiol. 1989 Jun;90(2):679–685. doi: 10.1104/pp.90.2.679. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Servaites J. C. Binding of a Phosphorylated Inhibitor to Ribulose Bisphosphate Carboxylase/Oxygenase during the Night. Plant Physiol. 1985 Aug;78(4):839–843. doi: 10.1104/pp.78.4.839. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vu C. V., Allen L. H., Bowes G. Effects of Light and Elevated Atmospheric CO(2) on the Ribulose Bisphosphate Carboxylase Activity and Ribulose Bisphosphate Level of Soybean Leaves. Plant Physiol. 1983 Nov;73(3):729–734. doi: 10.1104/pp.73.3.729. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wintermans J. F., de Mots A. Spectrophotometric characteristics of chlorophylls a and b and their pheophytins in ethanol. Biochim Biophys Acta. 1965 Nov 29;109(2):448–453. doi: 10.1016/0926-6585(65)90170-6. [DOI] [PubMed] [Google Scholar]