scholarly journals Reciprocal Control of Anaplerotic Phosphoenolpyruvate Carboxylase by in Vivo Monoubiquitination and Phosphorylation in Developing Proteoid Roots of Phosphate-Deficient Harsh Hakea

2013 ◽  
Vol 161 (4) ◽  
pp. 1634-1644 ◽  
Author(s):  
Michael W. Shane ◽  
Eric T. Fedosejevs ◽  
William C. Plaxton
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Proteoid Roots

Regulation of soybean nodule phosphoenolpyruvate carboxylase in vivo

1996 ◽  
Vol 97 (3) ◽  
pp. 531-535 ◽  
Author(s):  
Carol Wadham ◽  
Heike Winter ◽  
Kathryn A. Schuller
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Soybean Nodule

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.

The remarkable diversity of plant PEPC (phosphoenolpyruvate carboxylase): recent insights into the physiological functions and post-translational controls of non-photosynthetic PEPCs

2011 ◽  
Vol 436 (1) ◽  
pp. 15-34 ◽  
Author(s):  
Brendan O'Leary ◽  
Joonho Park ◽  
William C. Plaxton
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Tricarboxylic Acid Cycle ◽  
Critical Role ◽  
Subcellular Location ◽  
Serine Phosphorylation ◽  
Regulatory Subunit ◽  
Physiological Functions ◽  
Intrinsically Disordered ◽  
Class 1

PEPC [PEP (phosphoenolpyruvate) carboxylase] is a tightly controlled enzyme located at the core of plant C-metabolism that catalyses the irreversible β-carboxylation of PEP to form oxaloacetate and Pi. The critical role of PEPC in assimilating atmospheric CO2 during C4 and Crassulacean acid metabolism photosynthesis has been studied extensively. PEPC also fulfils a broad spectrum of non-photosynthetic functions, particularly the anaplerotic replenishment of tricarboxylic acid cycle intermediates consumed during biosynthesis and nitrogen assimilation. An impressive array of strategies has evolved to co-ordinate in vivo PEPC activity with cellular demands for C4–C6 carboxylic acids. To achieve its diverse roles and complex regulation, PEPC belongs to a small multigene family encoding several closely related PTPCs (plant-type PEPCs), along with a distantly related BTPC (bacterial-type PEPC). PTPC genes encode ~110-kDa polypeptides containing conserved serine-phosphorylation and lysine-mono-ubiquitination sites, and typically exist as homotetrameric Class-1 PEPCs. In contrast, BTPC genes encode larger ~117-kDa polypeptides owing to a unique intrinsically disordered domain that mediates BTPC's tight interaction with co-expressed PTPC subunits. This association results in the formation of unusual ~900-kDa Class-2 PEPC hetero-octameric complexes that are desensitized to allosteric effectors. BTPC is a catalytic and regulatory subunit of Class-2 PEPC that is subject to multi-site regulatory phosphorylation in vivo. The interaction between divergent PEPC polypeptides within Class-2 PEPCs adds another layer of complexity to the evolution, physiological functions and metabolic control of this essential CO2-fixing plant enzyme. The present review summarizes exciting developments concerning the functions, post-translational controls and subcellular location of plant PTPC and BTPC isoenzymes.

scholarly journals Relationship between NH+4 Assimilation Rate and in Vivo Phosphoenolpyruvate Carboxylase Activity

1990 ◽  
Vol 94 (1) ◽  
pp. 284-290 ◽  
Author(s):  
Greg C. Vanlerberghe ◽  
Kathryn A. Schuller ◽  
Ronald G. Smith ◽  
Regina Feil ◽  
William C. Plaxton ◽  
...  
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Assimilation Rate ◽  
Carboxylase Activity

Phosphoenolpyruvate carboxylase mediated carbon flow in a cyanobacterium

1988 ◽  
Vol 66 (2) ◽  
pp. 93-99 ◽  
Author(s):  
George W. Owttrim ◽  
Brian Colman
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Protein Production ◽  
Carbon Fixation ◽  
Fixed Carbon ◽  
Free System ◽  
Pyruvate Orthophosphate Dikinase ◽  
Orthophosphate Dikinase ◽  
Phosphoglyceric Acid ◽  
A Cell

The source of the substrate phosphoenolpyruvate (PEP) for phosphoenolpyruvate carboxylase (PEP-case) activity in the cyanobacterium Coccochloris peniocystis has been investigated, as well as possible sinks for this carbon. PEP was not produced by pyruvate orthophosphate dikinase, as this activity was not detectable in cell-free lysates. PEP is supplied from photosynthetically or glycolytically produced 3-phosphoglyceric acid (3-PGA), as carbon was observed to flow from 3-PGA to C4 acids in a cell-free system. This indicates PEP-case activity is dependent on photosynthetically fixed carbon and thus two separate carbon fixation reactions occur in the cell in the light. Estimates of the in vivo concentrations of various metabolites indicates that neither substrate nor inhibitor concentrations limit enzyme activity in vivo. Thus PEP-case activity in vivo appears to be limited by the supply of PEP and is, therefore, high in the light and low in the dark. The nitrogen storage product cyanophycin was identified as one sink for carbon fixed by PEP-case. As a culture aged, cyanophycin production increased, while chlorophyll and protein production decreased.

scholarly journals Bacterial- and plant-type phosphoenolpyruvate carboxylase isozymes from developing castor oil seeds interact in vivo and associate with the surface of mitochondria

2012 ◽  
Vol 71 (2) ◽  
pp. 251-262 ◽  
Author(s):  
Joonho Park ◽  
Nicholas Khuu ◽  
Alexander S. M. Howard ◽  
Robert T. Mullen ◽  
William C. Plaxton
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Castor Oil ◽  
Plant Type ◽  
Oil Seeds
Sign in / Sign up

Export Citation Format

Share Document