Regulation Of Phosphoenolpyruvate Carboxylase Research Articles

Phosphoenolpyruvate carboxylase regulation in C4-PEPC-expressing transgenic rice during early responses to drought stress.

Phosphoenolpyruvate carboxylase (PEPC; EC 4.1.1.31) has important functions in C4 photosynthesis and biosynthesis of intermediate metabolites. In this study, the drought resistance of C4-PEPC-expressing transgenic rice (Oryza sativa, line PC) plants was assessed using simulated drought conditions [i.e. polyethylene glycol (PEG)-6000 treatment]. The dry weight of PC plants was higher than that of wild-type (WT) plants following treatment with 15% PEG-6000 for 16 days. Furthermore, the water use efficiency, relative water content and proline content in PC plants were higher than those of WT plants, as were C4-PEPC activity and transcript levels following treatment with 5% PEG-6000 for 2 h. The protein kinase activities and transcript levels of sucrose non-fermenting-1-related protein kinases (SnRKs) genes, such as SnRK1a, OsK24 and OsK35 were also higher in PC plants than in WT plants following treatment with 5% PEG-6000 for 2 h. Additionally, phosphoenolpyruvate carboxylase kinase (PPCK, EC 4.1.1.32) activities and transcript levels (e.g. PPCK1 and PPCK2) increased following drought treatment. These changes were regulated by signaling molecules, such as calcium, nitric oxide and hydrogen peroxide. Furthermore, the -1095 to -416 region of the C4-PEPC promoter in PC plants was demethylated following exposure to drought conditions for 1 h. The demethylation coincided with an increase in C4-PEPC expression. Our data suggest that the demethylation of the C4-PEPC promoter and the phosphorylation catalyzed by PPCK have key roles in conferring drought tolerance to the transgenic rice plants.

Breed-dependent transcriptional regulation of phosphoenolpyruvate carboxylase, cystolic form, expression in the liver of broiler chickens

Hepatic gluconeogenesis is the main source of glucose during chicken embryonic development, and it plays a major role in glucose homeostasis for developing embryos. Phosphoenolpyruvate carboxylase (PEPCK) catalyzes the rate-limiting step of gluconeogenesis, yet how hepatic PEPCK expression is differentially regulated between chicken breeds remains elusive. In this study, fertile eggs from a slow-growing Chinese Yellow Feathered Chicken and a fast-growing White Recessive Rock Chicken were incubated under the same standard conditions, and serum and liver samples were collected on embryonic d 18 (18E). The fast-growing breed had a significantly higher fetal weight (P < 0.01) and serum glucose concentration (P < 0.05) compared with the slow-growing breed. The fast-growing breed also had significantly higher hepatic mRNA expression levels of the cystolic form of PEPCK (PEPCK-c; P < 0.05) and significantly higher hepatic mRNA and protein expression levels of cAMP response element binding protein 1 (CREB-1; P < 0.05). Moreover, the binding of phosphorylated CREB-1 to the PEPCK-c promoter tended to be higher in the fast-growing breed (P = 0.08). Breed-specific epigenetic modifications of the PEPCK-c promoter were also observed; the fast-growing breed demonstrated lower CpG methylation (P < 0.05) and histone H3 (P < 0.05) levels but more histone H3 acetylation (H3ac) and histone H3 lysine 27 trimethylation (H3K27me3; P < 0.05) compared with the slow-growing breed. Our results suggest that hepatic PEPCK-c expression is transcriptionally regulated in a breed-specific manner and that fast- and slow-growing broiler chicken fetuses exhibit different epigenetic modifications on their PEPCK-c promoter regions.

Regulation of phosphoenolpyruvate carboxylase in PVYNTN-infected tobacco plants

The effect of viral infection on the regulation of phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) in Nicotiana tabacum L. leaves was studied. PEPC activity was 3 times higher in infected plant leaves compared to healthy plants. Activity of plant PEPC can be regulated, e.g., by de novo synthesis or reversible phosphorylation. The reason for the increase of PEPC activity as a consequence of PVY(NTN) infection was studied. The amount of PEPC determined by Western blot analysis or by relative estimation of PEPC mRNA by real-time PCR did not differ in control and PVY(NTN)-infected plants. Changes in posttranslational modification of PEPC by phosphorylation were evaluated by comparing activity of the native and the dephosphorylated enzyme. The infected plants were characterized by a higher decrease of the enzyme activity after its dephosphorylation, which indicated a higher phosphorylation level. Immunochemical detection of phosphoproteins by Western blot analysis showed a more intensive band corresponding to PEPC from the infected material. This strengthens the hypothesis of an infection-related phosphorylation, which could be part of the plant's response to pathogen attack. The physiological implications of the increase in PEPC activity during PVY(NTN) infection are discussed.

The activities of PEP carboxylase and the C4 acid decarboxylases are little changed by drought stress in three C4 grasses of different subtypes

The C4 photosynthetic pathway involves the assimilation of CO2 by phosphoenolpyruvate carboxylase (PEPC) and the subsequent decarboxylation of C4 acids. The enzymes of the CO2 concentrating mechanism could be affected under water deficit and limit C4 photosynthesis. Three different C4 grasses were submitted to gradually induced drought stress conditions: Paspalum dilatatum (NADP-malic enzyme, NADP-ME), Cynodon dactylon (NAD-malic enzyme, NAD-ME) and Zoysia japonica (PEP carboxykinase, PEPCK). Moderate leaf dehydration affected the activity and regulation of PEPC in a similar manner in the three grasses but had species-specific effects on the C4 acid decarboxylases, NADP-ME, NAD-ME and PEPCK, although changes in the C4 enzyme activities were small. In all three species, the PEPC phosphorylation state, judged by the inhibitory effect of L-malate on PEPC activity, increased with water deficit and could promote increased assimilation of CO2 by the enzyme under stress conditions. Appreciable activity of PEPCK was observed in all three species suggesting that this enzyme may act as a supplementary decarboxylase to NADP-ME and NAD-ME in addition to its role in other metabolic pathways.

Expression of phosphoenolpyruvate carboxylase and phosphoenolpyruvate carboxylase kinase genes. Implications for genotypic capacity and phenotypic plasticity in the expression of crassulacean acid metabolism.

In plants with crassulacean acid metabolism (CAM), dark CO2 uptake is mediated by phosphoenolpyruvate carboxylase (PEPC), an enzyme that can be regulated at transcriptional and posttranslational levels. Reversible phosphorylation of PEPC is catalyzed by a dedicated PEPC kinase, which in turn is regulated at the transcriptional level over the 24-h cycle in CAM plants. PEPC kinase controls the day/night regulation of PEPC during the CAM cycle, thus facilitating plasticity for optimizing CO2 uptake under different environmental conditions. To understand the importance of PEPC kinase in relation to its target PEPC in terms of CAM performance, the expression of the genes encoding the two enzymes was investigated in four species of Clusia that have photosynthetic patterns ranging from C3 photosynthesis to constitutive CAM. By linking changes in the expression of PEPC and PEPC kinase to day/night patterns of leaf gas exchange, organic acid, and soluble sugar contents under different environmental conditions, the genetic and metabolic limitations to CAM plasticity were assessed. The results indicate that PEPC expression is a major factor underpinning the genotypic capacity for CAM and that PEPC kinase expression does not appear to limit CAM. The day/night regulation of Ppck transcript abundance was found to be a consequence of CAM and the day/night cycling of associated metabolites, rather than the primary controlling factor for the temporal separation of carboxylation processes.

How to tell the time: the regulation of phosphoenolpyruvate carboxylase in Crassulacean acid metabolism (CAM) plants.

Crassulacean acid metabolism (CAM) plants exhibit persistent circadian rhythms of CO(2) metabolism. These rhythms are driven by changes in the flux through phosphoenolpyruvate carboxylase, which is regulated by reversible phosphorylation in response to a circadian oscillator. This article reviews progress in our understanding of the circadian expression of phosphoenolpyruvate carboxylase kinase.

Regulation of phosphoenolpyruvate carboxylase in Pinus halepensis needles submitted to ozone and water stress

Effects of ozone and/or drought stresses on phosphoenolpyruvate carboxylase (PEPc, EC 4.1.1.31) regulation in Pinus halepensis Mill. needles were assessed over 3 months in controlled conditions. Whereas moderated water stress applied to Aleppo pine had no effect on PEPc activity compared to the control, which was probably related to the high tolerance of this species to drought, ozone stress induced a dramatic increase of PEPc activity in pine needles. This stimulation of the anaplerotic pathway could provide substrates to repair processes, well known for being enhanced upon ozone exposure. The ozone-increased PEPc activity was related, to a certain extent, to an increase in protein and mRNA levels. The possible role of the stimulation of the phosphorylation status of the enzyme in the increased PEPc activity under ozone was also investigated. Following the demonstration of the existence of the phosphorylation site at the N terminal part of Aleppo pine PEPc, it was shown that, under ozone treatment, the light/dark PEPc activity ratio and the Ki (malate) for PEPc were increased. This strengthens the hypothesis of an ozone-related post-translational process, which could be part of an adaptation of the plants to prolonged stress. When ozone and water stress were applied in combination, the enhancement in PEPc activity was only related to changes in gene expression. This difference in PEPc regulation, compared to the effect of single stress, could be the consequence of the specific action of each stress on the enzyme. This study brings new insights into the regulation of PEPc in a C3 plant, Aleppo pine under these stresses. A different regulatory mechanism of PEPc is occurring according to the stress. The physiological implications of the increase in PEPc activity in response to ozone and/or water stress are discussed.

Arabidopsis thaliana contains two phosphoenolpyruvate carboxylase kinase genes with different expression patterns

AbstractWe have already reported the cloning of one phosphoenolpyruvate carboxylase kinase gene from Arabidopsis thaliana (Hartwell et al. 1999, Plant Journal 20, 333–342), hereafter termed PPCK1. A second putative phosphoenolpyruvate carboxylase kinase gene (PPCK2) was identified in the Arabidopsis genome. The corresponding cDNA was amplified from flower tissue by reverse transcriptase (RT)‐polymerase chain reaction (PCR). This cDNA was transcribed and translated in vitro. The translation products possessed high phosphoenolpyruvate carboxylase kinase activity, confirming the identity of the PPCK2 gene. The expression of both phosphoenolpyruvate carboxylase kinase genes was examined by RT‐PCR. PPCK1 is mainly expressed in rosette leaves whereas PPCK2 is expressed in flowers and, at a lower level, in roots and cauline leaves. Light increased the expression of PPCK1 in rosette leaves and that of PPCK2 in flowers. The expression of both genes in an Arabidopsis cell culture was increased by treatment with cycloheximide. The data suggest that the two genes may have different roles in tissue‐specific regulation of phosphoenolpyruvate carboxylase.

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

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.

Regulation of Phosphoenolpyruvate Carboxylase in Zea mays by Protein Phosphorylation and Metabolites and Their Roles in Photosynthesis

The effects of metabolites, protein phosphorylation and malate inhibition on phosphoenolpyruvate carboxylase (PEPC) activity were investigated at pH 7.0 in partially purified enzyme from maize leaves. Glycine, glucose 6-phosphate or alanine stimulated the activity two- to three-fold. Glycine and glucose 6-phosphate increased the affinity for PEP by factors of eight and four respectively. These metabolites changed the response of the enzyme activity to pH. Activity increased between pH 6.8 and 8.0 by 10-fold in the absence and 26% in the presence of these metabolites. In vitro phosphorylation of PEPC increased the activity two-fold in the absence but not in the presence of these metabolites. Malate was a strong inhibitor of PEPC, the KI value being 0.25-0.5 mM. Protein phosphorylation and the above metabolites increased the Ki value by factors of three and 12 respectively, but they synergistically increased the Ki 50-fold, thus providing maximal protection against malate inhibition. In the crude extracts from light- and dark-adapted leaves in the presence of a physiological concentration of malate (20 mM), PEPC activity comparable to the photosynthetic rate was obtained only from the light-adapted leaves in the presence of metabolites indicating that both light-induced protein phosphorylation and metabolic activators were essential for PEPC activation during photosynthesis. We propose that both these factors act synergistically to modulate PEPC during photosynthesis in maize.

The Effect of pH on the Covalent and Metabolic Control of C 4 Phospho enolpyruvate Carboxylase from Sorghum Leaf

The influence of pH on the in vitro activity and regulatory properties of Sorghum leaf C 4 phospho enolpyruvate carboxylase (PEPC) was investigated with respect to the phosphorylation status of the enzyme. In vitro protein phosphorylation was achieved using the catalytic subunit of a cAMP-dependent protein kinase (PKA) and a recombinant, immunopurified PEPC (0.9 mol of covalent P i/mol PEPC subunit). Between pH 6.8 and 8, velocity and IC 50 for L-malate increased for both the nonphosphorylated and the phosphorylated forms. With respect to the nonphosphorylated PEPC, the phospho-PEPC always gave high values for these kinetic parameters at the pH range investigated, especially between pH 7 and 7.3. The phosphorylation-induced stimulation of PEPC activity was four- to fivefold at pH 7.1 and approximately twofold at pH 7.3. The IC 50 for L-malate showed a two- to threefold increase at pH 7.3, but varied less at pH 7.1 upon PEPC phosphorylation. Thus, phosphorylation of PEPC caused a predominant V effect or a mixed (V/IC 50) effect at pH 7.1 or 7.3, respectively. This was also observed with the enzyme from desalted crude protein extracts from dark or light-adapted Sorghum leaves and leaf-derived mesophyll protoplasts illuminated in the presence of methylamine, a compound known to increase cytosolic pH (pHc). At pH 7.3, desensitization to L-malate pf phospho-PEPC was due to an enhanced ability of PEP to compete with the inhibitor. The positive effector glucose-6P acted similarly to phosphorylation; however a combination of both factors (glucose-6P and phosphorylation) led to a much larger increase in the IC 50 for L-malate than that observed by a single factor. These effects may account for the actual CO 2 assimilation rate of an illuminated Sorghum leaf. In reconstituted assays performed at pH 7.1 or 7.3, in the presence of PKA, the addition of 10 mM L-malate decreased the phosphorylation rate of the PEPC. This effect was strongly inhibited by the addition of glucose-6P (5 mM). It is suggested that modulation of the phosphorylation rate is partly through conformational changes in the PEPC induced by these photosynthetic metabolites. Together with previous findings indicating that the photoinduction of PEPC protein kinase was strictly dependent on cytosolic alkalization in meosphyll cell protoplasts (J. N. Pierre et al., 1992, Eur. J. Biochem. 210, 531-537), the present data support the view that cytosolic pH is an important component of the overall regulation of PEPC in C 4-photosynthesis. Finally, the role of phosphorylation appears to be a mechanism to amplify the regulatory influences of pHc and glucose-6P on PEPC activity.

Quantitation of Rates of Transport, Metabolic Fluxes, and Cytoplasmic Levels of Inorganic Carbon in Maize Root Tips during K+ Ion Uptake

Our aim was to determine whether fixation of inorganic carbon (C(i)), due to phosphoenolpyruvate carboxylase activity, is limited by the availability of C(i) in the cytoplasm of maize (Zea mays L.) root tips. Rates of C(i) uptake and metabolism were measured during K(2)SO(4) treatment, which stimulates dark C(i) fixation. (13)C(i) uptake was followed by (13)C-nuclear magnetic resonance (NMR); 5 millimolar K(2)SO(4) had no significant effect on (13)C(i) influx. The contribution of respiratory CO(2) production to cytoplasmic HCO(3) (-) was measured using in vivo(13)C-NMR and (1)H-NMR of cell extracts; K(2)SO(4) treatment had no effect on respiratory CO(2) production. The concentration of cytoplasmic HCO(3) (-) was estimated to be approximately 11 millimolar, again with K(2)SO(4) having no significant effect. These experiments allowed us to determine the extent to which extracellularly supplied (14)C(i) was diluted in the cytoplasm by respiratory CO(2) and thereby measure phosphoenolpyruvate (PEP) carboxylase activity in vivo using (14)C(i). PEP carboxylase activity in root tips was enhanced approximately 70% over controls within 12 minutes of the addition of 5 millimolar K(2)SO(4). The activity of carbonic anhydrase, which provides PEP carboxylase with C(i), was determined by saturation transfer (13)C-NMR to be more than 200 times that of PEP carboxylase in vivo. The regulation of PEP carboxylase in K(2)SO(4)-treated roots is discussed.

Regulation of phospho enolpyruvate carboxylase from Crassula argentea: Effect of incubation with ligands and dilution on oligomeric state, activity, and allosteric properties

The relationship between the aggregation state and allosteric properties of purified phospho enolpyruvate carboxylase from Crassula argentea was examined using both kinetic and physical techniques. Analysis by native polyacrylamide gel electrophoresis showed that dilution induced a dissociation of the active tetramer to a less active dimer. Kinetic assays showed that inhibition of phospho enolpyruvate carboxylase by 5 m m malate measured at a saturating phospho enolpyruvate concentration rose to nearly 80% with increasing preassay dilution while the activity in the absence of malate remained constant. Kinetic bursts were observed when enzyme-initiated assays were measured at a subsaturating phospho enolpyruvate concentration. At saturating phospho enolpyruvate concentrations, however, increasing lags developed in response to increasing the preassay dilution of the enzyme. Further, dynamic laser-light scattering measurements showed that preincubation of the dilute enzyme with phospho enolpyruvate stabilized the tetramer while the presence of malate induced dimer formation. These observations confirm and extend earlier work with the extracted active malate insensitive night and less active, malate-sensitive day forms of the enzyme (Wu and Wedding [1985] Plant Physiol. 77, 667–675). Activity measured at subsaturating phospho enolpyruvate concentrations dropped with increasing preassay dilution of enzyme, while activation by 3.2 m m glucose 6-phosphate, assayed at a low phospho enolpyruvate concentration (0.044 m m), increased with dilution to nearly 400%. In this case activation results from a decrease in the control rate as the activity measured in the presence of glucose 6-phosphate was nearly constant, similar in effect to saturating phospho enolpyruvate in the assay. Glucose 6-phosphate induced tetramer formation of the dilute enzyme as measured by light-scattering similar to the effects induced by PEP. In addition, when diluted (dimeric) PEPC was preincubated with PEP or glucose 6-phosphate the enzyme became less sensitive to malate inhibition, while the active-site directed ligand 2-phosphoglycolate had no effect on malate inhibition. These results indicate that both the substrate PEP and the activator glucose 6-phosphate stabilize the active tetramer via binding and interaction at an activator site separate from the active site.

Regulation of phosphoenolpyruvate carboxylase: an example of signal transduction via protein phosphorylation in higher plants

There is now good evidence that the malate sensitivity of PEPc is regulated by phosphorylation/dephosphorylation in the leaf tissue of C 4 and CAM plants. This statement is based on the assessment of the phosphorylation state of PEPc in [ 32P]-labeled intact tissue by immunoprecipitation and the correlation between phosphorylation state and malate sensitivity that has been observed during incubation of purified PEPc in vitro with protein kinases or protein phosphatases. The phosphorylation of PEPc in the CAM plant B. fedtschenkoi is controlled by an endogenous rhythm whereas that PEPc in the C 4 plant maize is triggered directly by light. In neither case has the mechanism of signal transduction been identified. It is hoped that further work on the protein kinases and protein phosphatases involved will reveal the nature of the signalling systems. Preliminary work suggests that plant protein phosphatases are very similar to their mammalian counterparts. It is also noteworthy that higher plant genes very similar to the genes encoding the cyclic nucleotide-dependent protein kinases and the protein kinase C family have recently been identified (31). It is interesting to speculate that the protein kinases and phosphatases involved in signal transduction systems in plants may prove to be closely related to well-studied mammalian enzymes.

Regulation of Phosphoenolpyruvate Carboxylase in Crassulacean Acid Metabolism: In vitro Phosphorylation of the Enzyme

Summary The in vitro phosphorylation of PEP-carboxylase of the Crassulacean Acid Metabolism (CAM) plants Kalanchoe daigremontiana and K. blossfeldiana is reported in this paper. Phosphorylation was achieved by endogenous protein kinases. It leads to lowering of enzyme inhibition by the allosteric effector L-malate. The results support the hypothesis that reversible phosphorylation of the PEP-carboxylase protein is involved in the regulation of this enzyme during the day/night cycle of CAM.

Further Studies of the Short-term Regulation of Maize Leaf Phosphoenolpyruvate Carboxylase by Light

Summary An investigation was made of the interaction of maize leaf phosphoenolpyruvate carboxylase, in desalted extracts from light- and dark-treated plants, with its inhibitor malate and its allosteric activator glucose 6 P. The enzyme shows a much higher apparent affinity for malate and lower apparent affinity for glucose 6 P in dark than in light extracts. Therefore, these two metabolites could contribute to the in vivo short-term regulation of phosphoenolpyruvate carboxylase activity by light. In addition we determined the diurnal changes in total leaf content of malate, phosphoenolpyruvate and pyruvate as these changes may indicate those of phosphoenolpyruvate carboxylase activity in vivo . Levels of malate were found to decrease in the dark period, those of pyruvate increase markedly and transitorily during the first few minutes of this period, and those of phosphoenolpyruvate remain stable. These two latter results suggest that phosphoenolpyruvate carboxylase is rapidly dark-inactivated in vivo .

Regulation of Phosphoenolpyruvate Carboxylase from Crassula argentea

Phosphoenolpyruvate carboxylase in Crassulacean acid metabolism plants during the day exists in dimeric form the activity of which is strongly inhibited by malate. Enzyme purified from Crassula leaves collected during the day and stored at -70 degrees C for 49 days shows a steady progression of change from dimer to tetramer, and this change in oligomeric state is accompanied by a decrease in the sensitivity of the enzyme to inhibition by malate. At 10 minutes preincubation of enzyme after 11 days storage-which is composed of an equilibrium mixture of dimer and tetramer-with malate causes most of the enzyme to be converted to dimer and increases the sensitivity of the enzyme to malate inhibition during assay. Preincubation with phosphoenolpyruvate shifts the equilibrium toward the tetrameric form and reduces the maximal inhibition produced by 5 millimolar malate to less than 20%. However, none of the treatments used resulted in shifting the oligomerization equilibrium completely in either direction. Thus the question of whether some covalent modification of the enzyme, such as phosphorylation, is required to permit complete changes in equilibrium remains open.

Reduced Glutathione as an Effector of Phosphoenolpyruvate Carboxylase of the Crassulacean Acid Metabolism Plant Sedum praealtum D.C

Reduced glutathione, but not mercaptoethanol or dithiothreitol, inhibits phosphoenolpyruvate carboxylase (PEPC) in desalted leaf extracts from Sedum praealtum D.C. The inhibition is more evident at low pH values (< 7.2) and becomes increasingly smaller at higher pH. In the presence of the inhibitor, the hyperbolic rate curve of night PEPC is transformed to sigmoid and the S(0.5) is increased. When the enzyme is extracted during the day, the rate curve is sigmoid and it is not changed by the inhibitor, though the S(0.5) is further increased. Oxidized glutathione is completely inactive. Levels of reduced glutathione in leaf tissue are distinctly higher in the light. A role of photosynthetically reduced glutathione in the regulation of PEPC in Crassulacean acid metabolism species appears probable.

Regulation of phosphoenolpyruvate carboxylase in C 4 plants: Inhibition by pyrophosphate of the enzyme from Amaranthus viridis

Phosphoenolpyruvate carboxylase from the leaves of Amaranthus viridis was inhibited by pyrophosphate. The inhibition was competitive with respect to phosphoenolpyruvate ( K i 0.85 m m) and noncompetitive with respect to bicarbonate.

Regulation of phosphoenolpyruvate carboxylase from Acinetobacter calcoaceticus by nucleotides

FEBS LettersVolume 109, Issue 2 p. 202-204 Full-length articleFree Access Regulation of phosphoenolpyruvate carboxylase from Acinetobacter calcoaceticus by nucleotides K. Richter, K. Richter Section of Biological Sciences, Dept. of Biochemistry, Karl-Marx University, 701 Leipzig, GDRSearch for more papers by this authorH.-P. Kleber, H.-P. Kleber Section of Biological Sciences, Dept. of Biochemistry, Karl-Marx University, 701 Leipzig, GDRSearch for more papers by this author K. Richter, K. Richter Section of Biological Sciences, Dept. of Biochemistry, Karl-Marx University, 701 Leipzig, GDRSearch for more papers by this authorH.-P. Kleber, H.-P. Kleber Section of Biological Sciences, Dept. of Biochemistry, Karl-Marx University, 701 Leipzig, GDRSearch for more papers by this author First published: January 14, 1980 https://doi.org/10.1016/0014-5793(80)81086-6Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. References 1 M.F. Utter, H.M. Kolenbrander, P.D. Boyer The Enzymes 6, (1972), Academic Press New York 117– 168. 2 H.L. Kornberg, P.N. Campbell G.D. Greville Essays in Biochemistry 2, (1966), Academic Press London 16– 29. 3 E.R. Stadtman, P.D. Boyer The Enzymes 1, (1970), Academic Press New York 434– 439. 4 B.D. Sanwal, Bacteriol. Rev., 34, (1970), 20– 39. 5 R. Silverstein, M.S. Willis, J. Biol. Chem., 248, (1973), 8402– 8407. 6 R. Silverstein, Arch. Biochem. Biophys., 174, (1976), 568– 574. 7 K. Richter, Dipl.–Arb. (1976), Karl–Marx–Univ Leipzig 8 O.H. Lowry, N.J. Rosebrough, A.L. Farr, R. Randall, J. Biol. Chem., 193, (1951), 265– 275. 9 R.H. Millay, H. Schilling, L.B. Hersh, J. Biol. Chem., 253, (1978), 1371– 1377. 10 B.D. Sanwal, P. Maeba, J. Biol. Chem., 241, (1966), 4557– 4562. 11 K. Richter, H.-P. Kleber, Math.–Nat. R. 27, (1978), Wiss. Z. Karl–Marx–Univ Leipzig 93– 102. 12 J. Monod, J. Wyman, J.-P. Changeux, J. Mol. Biol., 12, (1965), 88– 118. 13 D.E. Atkinson, T.W. Goodwin Metabolic Roles of Citrate (1968), Academic Press New York 23– 40. 14 P. Maeba, B.D. Sanwal, J. Biol. Chem., 243, (1968), 448– 450. 15 H.L. Kornberg, M. Malcovati, FEBS Lett., 32, (1973), 257– 259. 16 E.R. Schwartz, L.J. Reed, Fed. Proc. FASEB, 27, (1968), 389– 391. 17 D.E. Atkinson, Science, 150, (1965), 851– 857. 18 H.-P. Kleber, FEBS Lett., 51, (1975), 274– 276. 19 K. Izui, J. Biochem., 68, (1970), 227– 238. 20 H. Teraoka, K. Izui, H. Katsuki, Biochemistry, 13, (1974), 5121– 5128. 21 M. Morikawa, K. Izui, H. Katsuki, Biochem. Biophys. Res. Commun., 45, (1971), 689– 694. 22 M.E. Kirtley, D.E. Koshland jr, J. Biol. Chem., 242, (1967), 4192– 4205. Citing Literature Volume109, Issue2January 14, 1980Pages 202-204 ReferencesRelatedInformation