NADPH‐dependent metabolism of the ribulose bisphosphate carboxylase/oxygenase inhibitor 2‐carboxyarabinitol 1‐phosphate by a chloroplast protein

Salvucci, Michael E.; Holbrook, Gabriel P.; Anderson, Joan C.; Bowes, George

doi:10.1016/0014-5793(88)80730-0

Cited by 30 publications

(37 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The total k,.t of Rubisco in S. oleracea was initially high (approximately 20 s') at the low PFD values of the early morning (Fig. 3C).…”

Section: Metabolite and Rubisco Analysesmentioning

confidence: 93%

“…As the PFD increased in the morning, in contrast to the other species the total k., of S. oleracea Rubisco decreased, reaching a minimum of 13 s-' at approximately 100 Mmol quanta m-2 s-'. As PFD increased further the total k.t then increased, attaining a maximum of approximately 20 s-' at 400 Mmol quanta m-2 s-'. The Rubisco total k.t of S. oleracea then remained relatively constant until the middle of the afternoon.…”

Section: Metabolite and Rubisco Analysesmentioning

confidence: 98%

“…This bound RuBP is presumably removed by another light-dependent enzyme, Rubisco activase (17). Bound CA1P in P. vulgaris and B. vulgaris is presumably removed by an NADPH-dependent chloroplastic enzyme (20).…”

Section: Rubp Levelsmentioning

confidence: 99%

See 2 more Smart Citations

Regulation of Ribulose-1,5-Bisphosphate Carboxylase Activity in Response to Diurnal Changes in Irradiance

Kobza¹,

Seemann²

1989

Plant Physiol.

View full text Add to dashboard Cite

The regulation of ribulose-1,5-bisphosphate (RuBP) carboxylase (Rubisco) activity and metabolite pool sizes in response to natural diumal changes in photon flux density (PFD) was examined in three species (Phaseolus vulgaris, Beta vulgaris, and Spinacia oleracea) known to differ in the mechanisms used for this regulation. Diumal regulation of Rubisco activity in P. vulgaris was primarily the result of metabolism of the naturally occurring tight-binding inhibitor of Rubisco, 2-carboxyarabinitol 1-phosphate (CAIP). In B. vulgaris, the regulation of Rubisco activity was the result of both changes in activation state and CAIP metabolism. In S. oleracea, Rubisco activity was regulated by a combination of changes in activation state and the binding/ release of another tight binding inhibitor, probably RuBP. Despite these different mechanisms for the light regulation of Rubisco activity, the relationship between the in vivo activity of Rubisco and the PFD was the same for all three species. Rates of CAIP metabolism were thus sufficient to allow this mechanism to participate in the diumal regulation of Rubisco activity as PFD changed at its normal rate. Furthermore, under natural conditions this regulatory mechanism was found to be important in controlling Rubisco activity over approximately the same range of PFD as did changes in activation state of the enzyme. Finally, this regulation of Rubisco activity resulted in relatively similar and saturating RuBP pool sizes for photosynthesis at all but the lowest PFD values in all three species.

show abstract

“…The total k,.t of Rubisco in S. oleracea was initially high (approximately 20 s') at the low PFD values of the early morning (Fig. 3C).…”

Section: Metabolite and Rubisco Analysesmentioning

confidence: 93%

Section: Metabolite and Rubisco Analysesmentioning

confidence: 98%

See 1 more Smart Citation

Regulation of Ribulose-1,5-Bisphosphate Carboxylase Activity in Response to Diurnal Changes in Irradiance

Kobza¹,

Seemann²

1989

Plant Physiol.

View full text Add to dashboard Cite

show abstract

“…The two effectors compete to produce a net catalytic rate. At a constant concentration of CA I -P, in the absence of Pi, 10 mm FBP stimulates During initial experiments on the isolation of CA 1-Pase, it was noted that maintenance of enzyme activity required storage in the presence of DTT (4,19). For this reason, most subsequent experiments with CA 1-Pase have also routinely included 4 mm DTT in the assay medium (7,20).…”

Section: Effect Of Fbp and Pi On Ca 1-pase Activitymentioning

confidence: 99%

Regulation of 2-Carboxyarabinitol 1-Phosphatase

Holbrook¹,

Galasinski²,

Salvucci³

1991

Plant Physiol.

Self Cite

View full text Add to dashboard Cite

The regulation of 2-carboxyarabinitol 1-phosphatase (CA 1-Pase) by phosphorylated effectors was studied with enzyme purified from tobacco (Nicotiana tabacum) leaves. CA 1-Pase activity was most stimulated by fructose 1,6-bisphosphate, exhibiting an Ao.5 value of 1.9 millimolar and a 10-fold enhancement of catalysis. With nbulose-1,5-bisphosphate, the AO.5 was 0.6 millimolar, and maximal stimulation of activity was 5.3-fold. Among the monophosphates, 3-phosphoglycerate and phosphoglycolate were more potent positive effectors than glyceraldehyde 3-phosphate, glucose 1-phosphate, glucose 6-phosphate, and dihydroxyacetone phosphate. Stimulation of CA 1-Pase by ribulose-1,5-bisphosphate and fructose 1,6-bisphosphate increased Vmax but did not appreciably alter Km (2-carboxyarabinitol 1-phosphate) values. Inorganic phosphate appeared to inhibit CA 1-Pase noncompetitively with respect to 2-carboxyarabinitol 1-phosphate, exhibiting a K, of 0.3 millimolar. The results suggest that these positive and negative effectors bind to a regulatory site on CA 1-Pase and may have a physiological role in the light regulation of this enzyme. Related experiments with CA 1-Pase inactivated by dialysis in the absence of dithiothreitol show that partial reactivation can be achieved in the presence of a range of reducing reagents, including dithiothreitol, cysteine, and reduced glutathione. This could imply an ancillary involvement of sulfhydryl reduction during light activation of CA 1-Pase in vivo. The enzyme was thermally stable up to 350C, in contrast to ribulose-1,5-bisphosphate carboxylase/oxygenase activase which lost activity above 300C. The activation energy for CA 1-Pase was calculated to be 56.14 kilojoules per mole.

show abstract

“…Archie agreed and Simon contacted Joe Berry, who kindly provided a sample for the experiments. Previous work on CA1P had shown that its release from Rubisco was very slow (Berry et al 1987) and that CA1Pase could only hydrolyze CA1P once it was released (Salvucci et al 1988). Robinson and Portis showed that activase was indeed active towards CA1P, facilitating its release from Rubisco to make it available for metabolism by CA1P phosphatase (Robinson and Portis 1988).…”

Section: Ca1p -A Red Herring?mentioning

confidence: 99%

The discovery of Rubisco activase — yet another story of serendipity

Portis¹,

Salvucci²

2005

Discoveries in Photosynthesis

Self Cite

View full text Add to dashboard Cite

A brief history of Rubisco (ribulose bisphosphate carboxylase oxygenase) research and the events leading to the discovery and initial characterization of Rubisco activase are described. Key to the discovery was the chance isolation of a novel Arabidopsis photosynthesis mutant. The characteristics of the mutant suggested that activation of Rubisco was not a spontaneous process in vivo, but involved a heritable factor. The search for the putative factor by 2D electrophoresis identified two polypeptides, genetically linked to Rubisco activation, that were missing in chloroplasts from the mutant. An assay for the activity of these polypeptides, which were given the name Rubisco activase, was developed after realizing the importance of including ribulose bisphosphate (RuBP) in the assay. The requirement for ATP and the subsequent identification of activase as an ATPase came about fortuitously, the result of a RuBP preparation that was contaminated with adenine nucleotides. Finally, the ability of activase to relieve inhibition of the endogenous Rubisco inhibitor, 2-carboxyarabinitol 1-phosphate, provided an early indication of the mechanism by which activase regulates Rubisco.Abbreviations: CA1P -2-carboxyarabinitol 1-phosphate; FBP -fructose bisphosphate; RuBP -ribulose bisphosphate; Rubisco -ribulose bisphosphate carboxylase oxygenase; Ru5P -ribulose 5-phosphate; SBP -sedoheptulose bisphosphate 'Much discussion, both inside and outside the lecture halls, centered upon the potentially important reports of endogenous compounds which inhibit or activate RuBPCO. The debate was fiercest over reports by M. Salvucci, A. Portis and co-workers of the presence in some tissues of a protein which is involved in the activation of RuBPCO. The suggestion that the protein is an enzyme, hence the name RuBPCO activase, appeared to raise some hackles.' J. A. M. Holtum and E. Latzko, 1987 Pre-activase history -a complex and schizophrenic RubiscoA brief look at some of the history of Rubisco research reveals a saga of surprises that will set an appropriate stage for describing the discovery of Rubisco activase. This most abundant plant protein masqueraded for many years as 'Fraction one' protein (Wildman and Bonner 1947;Kawashima and Wildman 1970) before its carboxylation activity was uncovered, beginning in 1954 (for historical accounts, see Weissbach and Horecker 1989; A.A. Benson, this issue; and S. Wildman, this issue). Many years later, its bifunctionality was revealed by discovery of its oxygenase activity (Bowes et al. 1971). The oxygenase

show abstract

NADPH‐dependent metabolism of the ribulose bisphosphate carboxylase/oxygenase inhibitor 2‐carboxyarabinitol 1‐phosphate by a chloroplast protein

Cited by 30 publications

References 19 publications

Regulation of Ribulose-1,5-Bisphosphate Carboxylase Activity in Response to Diurnal Changes in Irradiance

Regulation of Ribulose-1,5-Bisphosphate Carboxylase Activity in Response to Diurnal Changes in Irradiance

Regulation of 2-Carboxyarabinitol 1-Phosphatase

The discovery of Rubisco activase — yet another story of serendipity

Contact Info

Product

Resources

About