Regulation of pyruvate, orthophosphate dikinase by ADP-/Pi-dependent reversible phosphorylation in C3 and C4 plants

Chastain, Chris J.; Chollet, Raymond

doi:10.1016/s0981-9428(03)00065-2

Cited by 55 publications

(71 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…PPDK activity increased in assays to which Pi had been added while PPDK activity remained essentially linear in assays not containing added Pi. This Pi-dependent activation mechanism appears consistent with activation activities previously reported for plant PPDK [16,17] and bacterial PEPS [11]. In plants, the regulatory mechanism of PPDK involves the reversible phosphorylation of a threonine residue located in close proximity to the catalytic histidine [18], however, the amino acids involved in the regulation of the bacterial form of the enzyme have not been investigated.…”

Section: Inactivation and Activation Activities Of L Monocytogenes Pdrpsupporting

confidence: 87%

Identification of the amino acid involved in the regulation of bacterial pyruvate, orthophosphate dikinase and phosphoenolpyruvate synthetase

Tolentino¹,

Chastain²,

Burnell³

2013

ABC

View full text Add to dashboard Cite

Pyruvate, orthophosphate dikinase (PPDK) and phosphoenolpyruvate synthetase (PEPS) catalyze the conversion of pyruvate to phosphoenolpyruvate (PEP). Both are regulated by a phosphorylation-dephosphorylation mechanism involving a bifunctional serine/ threonine kinase and a pyrophosphorylase (PPDK regulatory protein, PDRP, and PEPS regulatory protein, PSRP, respectively). In plants the regulatory mechanism involves phosphorylation of a threonine residue that is separated by a single amino acid from the histidine residue that forms a phosphorylated intermediate during catalysis. Using antibodies, we demonstrated that the regulation of both Listeria monocytogenes PPDK and Escherichia coli PEP synthetase involves the phosphorylation of a threonine residue located close to the catalytic histidine residue. The amino acid located between the regulatory threonine and the catalytic histidine is highly conserved being serine in PPDK and cysteine in PEPS. Using site-directed mutagenesis we have shown that both PPDK and PEPS in which the serine and cysteine residues, respectively, were substituted with an alanine the enzymes could be regulated indicating that the serine and cysteine residues, respectively, are not essential for regulation. We also demonstrated that altering the intermediate amino acid did not alter the specificity of the regulatory proteins for their protein substrates.

show abstract

Section: Inactivation and Activation Activities Of L Monocytogenes Pdrpsupporting

confidence: 87%

Identification of the amino acid involved in the regulation of bacterial pyruvate, orthophosphate dikinase and phosphoenolpyruvate synthetase

Tolentino¹,

Chastain²,

Burnell³

2013

ABC

View full text Add to dashboard Cite

show abstract

“…In all plants, PPDK is located in both cytoplasmic and plastid compartments (Chastain and Chollet, 2003). Regulation of the bidirectional activities of C 4 PPDK has been proposed to be the consequence of light/darkmediated changes in the stromal ADP level via its action as a potent competitive inhibitor of the PDRP phospho-PPDK dephosphorylation function Chastain et al, 2011).…”

mentioning

confidence: 99%

Posttranslational Modification of Maize Chloroplast Pyruvate Orthophosphate Dikinase Reveals the Precise Regulatory Mechanism of Its Enzymatic Activity

Chen

Wang

et al. 2014

Plant Physiol.

View full text Add to dashboard Cite

In C 4 plants, pyruvate orthophosphate dikinase (PPDK) activity is tightly dark/light regulated by reversible phosphorylation of an active-site threonine (Thr) residue; this process is catalyzed by PPDK regulatory protein (PDRP). Phosphorylation and dephosphorylation of PPDK lead to its inactivation and activation, respectively. Here, we show that light intensity rather than the light/dark transition regulates PPDK activity by modulating the reversible phosphorylation at Thr-527 (previously termed Thr-456) of PPDK in maize (Zea mays). The amount of PPDK (unphosphorylated) involved in C 4 photosynthesis is indeed strictly controlled by light intensity, despite the high levels of PPDK protein that accumulate in mesophyll chloroplasts. In addition, we identified a transit peptide cleavage site, uncovered partial amino-terminal acetylation, and detected phosphorylation at four serine (Ser)/Thr residues, two of which were previously unknown in maize. In vitro experiments indicated that Thr-527 and Ser-528, but not Thr-309 and Ser-506, are targets of PDRP. Modeling suggests that the two hydrogen bonds between the highly conserved residues Ser-528 and glycine-525 are required for PDRP-mediated phosphorylation of the active-site Thr-527 of PPDK. Taken together, our results suggest that the regulation of maize plastid PPDK isoform (C 4 PPDK) activity is much more complex than previously reported. These diverse regulatory pathways may work alone or in combination to fine-tune C 4 PPDK activity in response to changes in lighting.

show abstract

“…The reverse reaction, if it happens to occur, may be assumed to rather involve the pyruvate Pi dikinase (PPDK; EC 2.7.9.1). This enzyme has recently been found and characterized in Arabidopsis leaves, in which there are two isoforms (cytosolic and chloroplastic; for review, see Chastain and Chollet, 2003). Furthermore, a light/dark regulation of the leaf enzyme involving phosphorylation has been demonstrated (Chastain et al, 2002).…”

mentioning

confidence: 99%

“…By contrast, chloroplastic PPDK is activated in the light due to its reversible dephosphorylation by Pi, which is in turn converted to PPi (Chastain et al, 2002;Chastain and Chollet, 2003). The inactivation of the enzyme involves phosphorylation by ADP, converted to AMP.…”

mentioning

confidence: 99%

Experimental Evidence of Phosphoenolpyruvate Resynthesis from Pyruvate in Illuminated Leaves

et al. 2011

View full text Add to dashboard Cite

Day respiration is the cornerstone of nitrogen assimilation since it provides carbon skeletons to primary metabolism for glutamate (Glu) and glutamine synthesis. However, recent studies have suggested that the tricarboxylic acid pathway is rate limiting and mitochondrial pyruvate dehydrogenation is partly inhibited in the light. Pyruvate may serve as a carbon source for amino acid (e.g. alanine) or fatty acid synthesis, but pyruvate metabolism is not well documented, and neither is the possible resynthesis of phosphoenolpyruvate (PEP). Here, we examined the capacity of pyruvate to convert back to PEP using 13 C and 2 H labeling in illuminated cocklebur (Xanthium strumarium) leaves. We show that the intramolecular labeling pattern in Glu, 2-oxoglutarate, and malate after 13 C-3-pyruvate feeding was consistent with 13 C redistribution from PEP via the PEPcarboxylase reaction. Furthermore, the deuterium loss in Glu after 2 H 3 -13 C-3-pyruvate feeding suggests that conversion to PEP and back to pyruvate washed out 2 H atoms to the solvent. Our results demonstrate that in cocklebur leaves, PEP resynthesis occurred as a flux from pyruvate, approximately 0.5‰ of the net CO 2 assimilation rate. This is likely to involve pyruvate inorganic phosphate dikinase and the fundamental importance of this flux for PEP and inorganic phosphate homeostasis is discussed.

show abstract

Regulation of pyruvate, orthophosphate dikinase by ADP-/Pi-dependent reversible phosphorylation in C3 and C4 plants

Cited by 55 publications

References 38 publications

Identification of the amino acid involved in the regulation of bacterial pyruvate, orthophosphate dikinase and phosphoenolpyruvate synthetase

Identification of the amino acid involved in the regulation of bacterial pyruvate, orthophosphate dikinase and phosphoenolpyruvate synthetase

Posttranslational Modification of Maize Chloroplast Pyruvate Orthophosphate Dikinase Reveals the Precise Regulatory Mechanism of Its Enzymatic Activity

Experimental Evidence of Phosphoenolpyruvate Resynthesis from Pyruvate in Illuminated Leaves

Contact Info

Product

Resources

About