scholarly journals In Vivo Regulatory Phosphorylation Site in C4-Leaf Phosphoenolpyruvate Carboxylase from Maize and Sorghum

1991 ◽  
Vol 96 (1) ◽  
pp. 297-301 ◽  
Author(s):  
Jin-an Jiao ◽  
Jean Vidal ◽  
Cristina Echevarría ◽  
Raymond Chollet
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Phosphorylation Site ◽  
Regulatory Phosphorylation

Phosphoenolpyruvate carboxylase during grape berry development: protein level, enzyme activity and regulation

2000 ◽  
Vol 27 (3) ◽  
pp. 221 ◽  
Author(s):  
Paraskevi Diakou ◽  
Laurence Svanella ◽  
Philippe Raymond ◽  
Jean-Pierre Gaudillère ◽  
Annick Moing
Keyword(s):  
Malic Acid ◽  
Protein Level ◽  
Phosphoenolpyruvate Carboxylase ◽  
Phosphorylation Site ◽  
Acid Synthesis ◽  
Grape Berry ◽  
Vitis Vinifera L ◽  
Normal Acid

The protein level and regulation of phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31, involved in malic acid synthesis) was studied during the fruit development of two grape (Vitis vinifera L.) varieties, ‘Cabernet Sauvignon’ and ‘Gora Chirine’, with berries of normal and low organic acid content, respectively. The protein level and in vitro activity were higher in the low-acid variety than in the normal-acid variety for most stages. In vivo PEPC activity, measured using 14 CO2 labelling, was significantly higher in the low-acid variety than in the normal-acid variety about 1 week before and 1 week after veraison (the day which corresponds to the onset of ripening). However, partitioning into malate was the same for both varieties. Antibodies raised against the N-terminal part of SorghumPEPC recognised the grape berry PEPC, indicating the presence of the consensus phosphorylation site involved in PEPC regulation. PEPC phosphorylation status was estimated by studying sensitivity to pH and malate. Grape berry PEPC appeared more sensitive to low pH and malate during ripening (IC50 malate, 0.2–0.7 mM) compared to during the earlier stages of development (IC50 malate, 1.2–2 mM) for both varieties. Therefore, in the normal-acid variety, PEPC seems to participate in controlling malic acid accumulation but does not seem to control the differences in malic acid concentration observed between the two varieties.

Regulatory phosphorylation of C4 phosphoenolpyruvate carboxylase from Sorghum: An immunological study using specific anti-phosphorylation site-antibodies

1995 ◽  
Vol 43 (3) ◽  
pp. 283-288 ◽  
Author(s):  
Val�rie Pacquit ◽  
Nathalie Giglioli ◽  
Claude Cr�tin ◽  
Jean Noel Pierre ◽  
Jean Vidal ◽  
...  
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Phosphorylation Site ◽  
Immunological Study ◽  
Regulatory Phosphorylation

scholarly journals Characterization of novel mutations at the Schizosaccharomyces pombe cdc2 regulatory phosphorylation site, tyrosine 15.

1996 ◽  
Vol 7 (10) ◽  
pp. 1573-1586 ◽  
Author(s):  
K L Gould ◽  
A Feoktistova
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Phosphorylation Site ◽  
Loss Of Function ◽  
Contractile Ring ◽  
Mutant Proteins ◽  
Regulatory Phosphorylation ◽  
Binding Loop

The cdc2 protein kinase family is regulated negatively by phosphorylation in the glycine ATP-binding loop at a conserved tyrosine residue, Y15, alone or in combination with T14 phosphorylation. In Schizosaccharomyces pombe and other systems, substitution of these residues with structurally similar but nonphosphorylatable amino acids has generated proteins (Y15F or T14AY15F) that behave as constitutively tyrosine-dephosphorylated proteins or threonine and tyrosine-dephosphorylated proteins. Here we report the characteristics of three additional mutants at Y15--Y15E, Y15S, and Y15T--in S. pombe cdc2p. All three mutant proteins are active in in vitro kinase assays, but are unable to functionally complement cdc2 loss-of-function mutations in vivo. Additionally, all three mutants are dominant negatives. A more detailed analysis of the Y15T mutant indicates that it can initiate chromosome condensation and F-actin contractile ring formation, but is unable to drive the reorganization of microtubules into a mitotic spindle.

The bacterial-type phosphoenolpyruvate carboxylase isozyme from developing castor oil seeds is subject to in vivo regulatory phosphorylation at serine-451

FEBS Letters ◽  
2012 ◽  
Vol 586 (7) ◽  
pp. 1049-1054 ◽  
Author(s):  
Katie J. Dalziel ◽  
Brendan O'Leary ◽  
Carolyne Brikis ◽  
Srinath K. Rao ◽  
Yi-Min She ◽  
...  
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Castor Oil ◽  
Oil Seeds ◽  
Regulatory Phosphorylation ◽  
Bacterial Type

scholarly journals In vivo regulatory phosphorylation of the phosphoenolpyruvate carboxylase AtPPC1 in phosphate-starved Arabidopsis thaliana

2009 ◽  
Vol 420 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Allison L. Gregory ◽  
Brenden A. Hurley ◽  
Hue T. Tran ◽  
Alexander J. Valentine ◽  
Yi-Min She ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Phosphoenolpyruvate Carboxylase ◽  
Specific Activity ◽  
Phosphorylation Site ◽  
Gel Filtration ◽  
Growth Media ◽  
Suspension Cells ◽  
Apparent Homogeneity ◽  
Genes Encoding

PEPC [PEP(phosphoenolpyruvate) carboxylase] is a tightly controlled cytosolic enzyme situated at a major branchpoint in plant metabolism. Accumulating evidence indicates important functions for PEPC and PPCK (PEPC kinase) in plant acclimation to nutritional Pi deprivation. However, little is known about the genetic origin or phosphorylation status of native PEPCs from −Pi (Pi-deficient) plants. The transfer of Arabidopsis suspension cells or seedlings to −Pi growth media resulted in: (i) the marked transcriptional upregulation of genes encoding the PEPC isoenzyme AtPPC1 (Arabidopsis thaliana PEPC1), and PPCK isoenzymes AtPPCK1 and AtPPCK2; (ii) >2-fold increases in PEPC specific activity and in the amount of an immunoreactive 107-kDa PEPC polypeptide (p107); and (iii) In vivo p107 phosphorylation as revealed by immunoblotting of clarified extracts with phosphosite-specific antibodies to Ser-11 (which could be reversed following Pi resupply). Approx. 1.3 mg of PEPC was purified 660-fold from −Pi suspension cells to apparent homogeneity with a specific activity of 22.3 units · mg−1 of protein. Gel filtration, SDS/PAGE and immunoblotting demonstrated that purified PEPC exists as a 440-kDa homotetramer composed of identical p107 subunits. Sequencing of p107 tryptic and Asp-N peptides by tandem MS established that this PEPC is encoded by AtPPC1. Pi-affinity PAGE coupled with immunoblotting indicated stoichiometric phosphorylation of the p107 subunits of AtPPC1 at its conserved Ser-11 phosphorylation site. Phosphorylation activated AtPPC1 at pH 7.3 by lowering its Km(PEP) and its sensitivity to inhibition by L-malate and L-aspartate, while enhancing activation by glucose 6-phosphate. Our results indicate that the simultaneous induction and In vivo phosphorylation activation of AtPPC1 contribute to the metabolic adaptations of −PiArabidopsis.

scholarly journals In Vivo Regulatory Phosphorylation of Novel Phosphoenolpyruvate Carboxylase Isoforms in Endosperm of Developing Castor Oil Seeds

2005 ◽  
Vol 139 (2) ◽  
pp. 969-978 ◽  
Author(s):  
Karina E. Tripodi ◽  
William L. Turner ◽  
Sam Gennidakis ◽  
William C. Plaxton
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Castor Oil ◽  
Oil Seeds ◽  
Regulatory Phosphorylation

scholarly journals Phosphorylation of bacterial-type phosphoenolpyruvate carboxylase at Ser425 provides a further tier of enzyme control in developing castor oil seeds

2010 ◽  
Vol 433 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Brendan O'Leary ◽  
Srinath K. Rao ◽  
William C. Plaxton
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Castor Oil ◽  
Vascular Plant ◽  
Phosphorylation Site ◽  
Physiological Status ◽  
Spectrometric Analysis ◽  
Oil Seeds ◽  
Class 1 ◽  
Bacterial Type

PEPC [PEP (phosphoenolpyruvate) carboxylase] is a tightly controlled anaplerotic enzyme situated at a pivotal branch point of plant carbohydrate metabolism. Two distinct oligomeric PEPC classes were discovered in developing COS (castor oil seeds). Class-1 PEPC is a typical homotetramer of 107 kDa PTPC (plant-type PEPC) subunits, whereas the novel 910-kDa Class-2 PEPC hetero-octamer arises from a tight interaction between Class-1 PEPC and 118 kDa BTPC (bacterial-type PEPC) subunits. Mass spectrometric analysis of immunopurified COS BTPC indicated that it is subject to in vivo proline-directed phosphorylation at Ser425. We show that immunoblots probed with phosphorylation site-specific antibodies demonstrated that Ser425 phosphorylation is promoted during COS development, becoming maximal at stage IX (maturation phase) or in response to depodding. Kinetic analyses of a recombinant, chimaeric Class-2 PEPC containing phosphomimetic BTPC mutant subunits (S425D) indicated that Ser425 phosphorylation results in significant BTPC inhibition by: (i) increasing its Km(PEP) 3-fold, (ii) reducing its I50 (L-malate and L-aspartate) values by 4.5- and 2.5-fold respectively, while (iii) decreasing its activity within the physiological pH range. The developmental pattern and kinetic influence of Ser425 BTPC phosphorylation is very distinct from the in vivo phosphorylation/activation of COS Class-1 PEPC's PTPC subunits at Ser11. Collectively, the results establish that BTPC's phospho-Ser425 content depends upon COS developmental and physiological status and that Ser425 phosphorylation attenuates the catalytic activity of BTPC subunits within a Class-2 PEPC complex. To the best of our knowledge, this study provides the first evidence for protein phosphorylation as a mechanism for the in vivo control of vascular plant BTPC activity.

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