Apicomplexan parasites predominantly generate ATP and lactic acid through glycolysis and anaerobic glucose metabolism,incorporating CO_(2) into glycolysis via a stage-dependent phosphoenolpyruvate carboxylase(PEPC)mec...Apicomplexan parasites predominantly generate ATP and lactic acid through glycolysis and anaerobic glucose metabolism,incorporating CO_(2) into glycolysis via a stage-dependent phosphoenolpyruvate carboxylase(PEPC)mechanism.Although the role of PEPC in plant and bacterial carbon fixation is well documented,its function within Babesia remains largely unexplored.This study employs reverse genetics to probe the biological role of PEPC in Babesia gibsoni,noting its conservation across similar protozoa,suggesting a pivotal and conserved biological function.Western blotting and immunofluorescence(IFA)experiments using the BgPEPC-3×Flag strain revealed that the BgPEPC protein has a molecular weight of 105 kDa and localizes predominantly to the cytoplasm.Attempts to knock out the PEPC gene in BgPEPC-3×Flag strains failed under standard media conditions,succeeded only with the addition of 5 mM malate,an upstream metabolite of oxaloacetic acid(OAA).In addition to malate,the downstream metabolite of OAA can also partially compensate for the phenotypic defects caused by PEPC deficiency.This intervention alleviated severe growth deficits,underscoring the critical role of aspartate in the parasite lifecycle.Moreover,metabolic inhibitors such as L-cycloserine and triazamidine,which target aspartate aminotransferase and mitochondrial functions,respectively,demonstrated increased efficacy against BgPEPC knockout strains.The lack of a compensatory response to malic acid supplementation underscores the integral role of BgPEPC in intermediary carbon metabolism and its necessity in providing aspartate as a precursor to pyrimidine synthesis.Collectively,these findings suggest that PEPC could be a potential target for future drug development against B.gibsoni infections.展开更多
[ Objective] The aim of this study was to introduce Phosphoenolpyruvate Carboxylase （PEPCase） gene into common wheat Linyou 145. [ Method] With the material of common wheat Linyou 145, Phosphoenolpyruvate Carboxyla...[ Objective] The aim of this study was to introduce Phosphoenolpyruvate Carboxylase （PEPCase） gene into common wheat Linyou 145. [ Method] With the material of common wheat Linyou 145, Phosphoenolpyruvate Carboxylase （PEPCase） gene was introduced into wheat embryo callus by the agrobacterium-mediated transformation system, and then analyzed through successive selection with selective medium con- taing gygrornycin to detect the gene at the molecular level. [Result] The hyg-resistant plants were obtained, and GUS histochemical staining showed the leaf of resistant plants was stained dark blue. The target bands appeared in PCR analysis. [ Conclusion] Phosphoenolpyruvate Car- boxylase （PEPCase） gene has been primarily introduced into the recipient material.展开更多
Saccharina japonica is a common macroalga in sublittoral communities of cold seawater environments, and consequently may have highly efficient ribulose-1, 5-bisphosphate carboxylase/ oxygenase （Rubisco） activity for...Saccharina japonica is a common macroalga in sublittoral communities of cold seawater environments, and consequently may have highly efficient ribulose-1, 5-bisphosphate carboxylase/ oxygenase （Rubisco） activity for carbon assimilation. In our study, we cloned the full-length Rubisco gene from S.japonica （SJ-rbc）. It contained an open reading frame for a large subunit gene （SJ-rbcL） of 1 467 bp, a small subunit gene （SJ-rbcS） of 420 bp, and a SJ-rbcL/S intergenie spacer of 269 bp. The deduced peptides of SJ-rbcL and SJ-rbcS were 488 and 139 amino acids with theoretical molecular weights and isoelectric points of 53.97 kDa, 5.81 and 15,84 kDa, 4.71, respectively. After induction with 1 mmol/L isopropyl-β-D- thiogalactopyranoside for 5 h and purification by Ni2＋ affinity chromatography, electrophoresis and western blot detection demonstrated successful expression of the 55 kDa SJ-rbcL protein. Real-time quantitative PCR showed that the mRNA levels of SJ-rbcL in gametophytes increased when transferred into normal growth conditions and exhibited diurnal variations： increased expression during the day but suppressed expression at night. This observation implied that Rubisco played a role in normal gametophytic growth and development. In juvenile sporophytes, mRNA levels of SJ-rbcL, carbonic anhydrase, Calvin-Benson- Bassham cycle-related enzyme, and chloroplast light-harvesting protein were remarkably increased under continuous light irradiance. Similarly, expression of these genes was up-regulated under blue light irradiance at 350 umol/（m2.s）. Our results indicate that long-term white light and short-term blue light irradiance enhances juvenile sporophytic growth by synergistic effects of various photosynthetic elements.展开更多
Phosphoenolpyruvate carboxylase （PEPC） is widely distributed in plants and bacteria, and catalyzes the carboxylation of phosphoenolpyruvate to form oxaloacetate and inorganic phosphate. To investigate the molecular ...Phosphoenolpyruvate carboxylase （PEPC） is widely distributed in plants and bacteria, and catalyzes the carboxylation of phosphoenolpyruvate to form oxaloacetate and inorganic phosphate. To investigate the molecular mechanisms of the regulation and control of peanut oil, with the degenerated primers and RACE-PCR approach, five PEPC genes were cloned from peanut, and designated as AhPEPC1, AhPEPC2, AhPEPC3, AhPEPC4, and AhPEPC5, respectively. The structure and phylogenetic analysis of PEPC protein indicated that AhPEPC1-4 genes encoded a typical plant-type PEPC-enzyme, and AhPEPC5 a bacterial-type. By real-time quantitative RT-PCR approach the expression pattern of each gene was detected in various tissues of normal and high oil-content peanut varieties. It was found that there was a lower expression level of AhPEPCs genes except for the AhPEPC2 in high-oil peanut than normal-oil peanut line. The results provide some fundamental information for the further investigation of plant PEPC proteins and their role in regulation of oil-content in peanut seeds.展开更多
Phosphoenolpyruvate carboxylase（PEPC;EC 4.1.1.31） catalyses phosphoenolpyruvate（PEP） to yield oxaloacetate,which is involved in protein biosynthesis.Pyruvate kinase（PK;EC 2.7.1.40） catalyzes PEP to yield pyruvat...Phosphoenolpyruvate carboxylase（PEPC;EC 4.1.1.31） catalyses phosphoenolpyruvate（PEP） to yield oxaloacetate,which is involved in protein biosynthesis.Pyruvate kinase（PK;EC 2.7.1.40） catalyzes PEP to yield pyruvate,which is involved in fatty acid synthesis.In this study,five PEPC genes（AhPEPC1,AhPEPC2,AhPEPC3,AhPEPC4,and AhPEPC5） from peanut have been cloned.Using a quantitative real-time RT-PCR approach,the expression pattern of each gene was monitored during the seed development of four peanut varieties（E11,Hebeigaoyou,Naihan 1,and Huayu 26）.It was found that these five genes shared similar expression behaviors over the developmental stages of E11 with high expression levels at 30 and 40 d after pegging（DAP）;whereas these five genes showed irregular expression patterns during the seed development of Hebeigaoyou.In Naihan 1 and Huayu 26,the expression levels of the five genes remained relatively high in the first stage.The PEPC activity was monitored during the seed development of four peanut varieties and seed oil content was also characterized during whole period of seed development.The PEPC activity followed the oil accumulation pattern during the early stages of development but they showed a significantly negative correlation thereafter.These results suggested that PEPC may play an important role in lipid accumulation during the seed development of four peanut varieties tested.展开更多
De novo lipogenesis(DNL)plays an important role in the pathogenesis of hepatic steatosis and also appears to be implicated in hepatic inflammation and fibrosis.Accordingly,the inhibition of acetyl-CoA carboxylase,whic...De novo lipogenesis(DNL)plays an important role in the pathogenesis of hepatic steatosis and also appears to be implicated in hepatic inflammation and fibrosis.Accordingly,the inhibition of acetyl-CoA carboxylase,which catalyzes the ratelimiting step of DNL,might represent a useful approach in the management of patients with nonalcoholic fatty liver disease(NAFLD).Animal studies and preliminary data in patients with NAFLD consistently showed an improvement in steatosis with the use of these agents.However,effects on fibrosis were variable and an increase in plasma triglyceride levels was observed.Therefore,more longterm studies are needed to clarify the role of these agents in NAFLD and to determine their risk/benefit profile.展开更多
Three F3 hybrids derived from the sterile rice lines Gang 46A, 776A and 2480A and the improved restorer line Shuhui 881 containing maize phosphoenolpyruvate carboxylase （pepc） gene were used to analyze the effect of...Three F3 hybrids derived from the sterile rice lines Gang 46A, 776A and 2480A and the improved restorer line Shuhui 881 containing maize phosphoenolpyruvate carboxylase （pepc） gene were used to analyze the effect of pepc gene on the heterosis and photosynthetic characteristics, while the F3 obtained by crossing Shuhui 881 with the above three sterile lines served as controls. The dynamics of photosynthetic characteristics in leaves of three F1 with pepc gene and their controls were determined at the initial-tillering, maxium-tillering, elongation, initial-heading, heading, maturity stages, and other different times after flag leaf fully expanded. The PEPCase activities of the three F1 with pepc gene increased significantly as compared with control plants during the whole developmental stages. Moreover, the net photosynthesis rate （Pn） also increased to certain extent. The data showed that PEPCase activity was significantly correlated to Pn with a correlation coefficient of 0.6081. The photosynthetic indexes of the three F1 with pepc gene were obviously superior to respective controls in apparent quantum efficiency, light compensation point and carboxylation efficiency, while the CO2 compensation point was lower than that of corresponding control. The Pn of the three F1 with pepc gene at light saturation point and CO2 saturation point was also higher than that of control plants. in addition, the three F1 with pepc gene had an average increase of 37.10% in grain yields per plant in comparison with control plants. The results indicated that the photosynthetic characteristics of hybrid rice containing pepc gene had been improved to some extent due to the introduction of pepc gene.展开更多
To investigate the exon mutation of vitamin K-dependent gamma-glutamyl carboxylase （GGCX or VKDC） in patients with calcium oxalate urolithasis, renal cortex and peripheral blood samples were obtained from severe hyd...To investigate the exon mutation of vitamin K-dependent gamma-glutamyl carboxylase （GGCX or VKDC） in patients with calcium oxalate urolithasis, renal cortex and peripheral blood samples were obtained from severe hydronephrosis patients （with or without calculi）, and renal tumor patients undergoing nephrectomy. GGCX mutations in all 15 exons were examined in 44 patients with calcium oxalate urolithiasis （COU） by polymerase chain reaction （PCR） and denatured high pressure liquid chromatography （DHPLC）, and confirmed by sequencing. Mutation was not found in all COU samples compared to the controls. These data demonstrated that functional GGCX mutations in all 15 exons do not occur in most COU patients. It was suggested that there may be no significant association between the low activity and mutation of GGCX in COU.展开更多
The entire gene of carboxyltransferase（CT） domain of acetyl-CoA carboxylase（ACCase） from Chinese Spring wheat（CSW） plastid was cloned firstly, and the 2.3 kb gene was inserted into PET28a^＋ vector and expressed...The entire gene of carboxyltransferase（CT） domain of acetyl-CoA carboxylase（ACCase） from Chinese Spring wheat（CSW） plastid was cloned firstly, and the 2.3 kb gene was inserted into PET28a^＋ vector and expressed in E. coil in a soluble state. The （His）6 fusion protein was identified by SDS-PAGE and Western blot. The recombinant protein was purified by affinity chromatography, and the calculated molecular mass（Mr） was 88000. The results of the sequence analysis indicate that the cloned gene（GeneBank accession No. EU124675） was a supplement and revision of the reported ACCase CT partial cDNA from Chinese Spring wheat plastid. The recombinant protein will be significant for us to investigate the recognizing mechanism between ACCase and herbicides, and further to screen new herbicides.展开更多
This study was conducted using seeds in Petri dish containing agar medium in order to determine acetyl-CoA carboxylase （ACCase） herbicides resistance （R） in Avena sterilis that was grown in wheat fields at Adana p...This study was conducted using seeds in Petri dish containing agar medium in order to determine acetyl-CoA carboxylase （ACCase） herbicides resistance （R） in Avena sterilis that was grown in wheat fields at Adana province, Turkey. Seeds were collected from one large suspected field, where clodinafop-propargyl （Aryloxyphenoxypropionate “FOPs”） and pinoxaden （Phenylpyrazoline “DEN”） have been applied for many years. Susceptible （S） population was collected from the road side on the same region. Agar media of concentration 14 g/L was prepared and it was melted in microwave. Then the amount of 20 mL agar media was added into each Petri dish. Five seeds were placed on agar mediums containing discriminating dose of clodinafop and pinoxaden. Petri dishes were placed in growth incubator operating at 10 °C. After 15 d, both radicle and hypocotyl length were measured. The percentage of germinated seed and dose-response curves were determined. At these different concentration levels, there were more than 50% of R and less than 40% of S seed germinated for pinoxaden. However, for clodinafop, more than 60% of R and less than 50% of S seeds were germinated. At higher concentration levels, the populations of resistant and susceptible were not germinated for both herbicides. The resistance value of R population was then compared with that of the S biotype. From the resistance index （RI）, the population was more resistant to pinoxaden （7.43 for radicle and 2.47 for hypocotyl） than the clodinafop-propagyl （1.39 for radicle and 3.77 for hypocotyl）. The method provided a simple, quick and cost effective way to identify ACCase herbicides resistance in most grass weeds.展开更多
Wheat seed storage protein is of great importance for human food. To increase the contents of storage proteins effectively, nitrogen fertilizer at flowering stages is commonly applied. In our previous study, rice phos...Wheat seed storage protein is of great importance for human food. To increase the contents of storage proteins effectively, nitrogen fertilizer at flowering stages is commonly applied. In our previous study, rice phosphoenolpyruvate carboxylase (PEPCase) activity in developing seeds was observed in response to nitrogen application at a flowering stage and was positively correlated to the response of the protein content in seeds of six cultivars. This observation might indicate that the seeds have a biological system for accepting nitrogen in seeds by using PEPCase. To test whether this physiological event occurs in wheat, we examined the PEPCase activity and protein content in field-grown wheat seeds under different nitrogen supply conditions. With only basal dressing, seeds showed lower PEPCase activity and protein content (both 0.90-fold) compared to seeds without basal fertilizer. With ammonium sulfate application at 8.3 and 25 g/m2 at a flowering stage, seeds showed higher PEPCase activity (1.08- and 1.17-fold, respectively) and protein content (1.15- and 1.42-fold, respectively), depending on the nitrogen level. We investigated the relationship between PEPCase activity and protein content in the seeds among four conditions. The effect of the nitrogen supply on PEPCase activity during grain-filling stages was validated by the results of a hydroponic culture experiment. Together the results demonstrate that our hypothesis seems to apply to field-grown wheat.展开更多
In mammalian skeletal muscle there are four carboxylases involved in several biochemical processes like gluconeogenesis, tricarboxylic acid cycle anaplerosis, metabolism of fatty acids and metabolism of various amino ...In mammalian skeletal muscle there are four carboxylases involved in several biochemical processes like gluconeogenesis, tricarboxylic acid cycle anaplerosis, metabolism of fatty acids and metabolism of various amino acids. It has been shown that biotin deficiency reduces body weight at the expense of muscular mass. When necessary, the liver uses skeletal muscle protein to provide glucose and amino acids to organs in need of such compounds. In this paper we analyzed carboxylase specific activities in hind limb skeletal muscle of 3 weeks old BALB/c male mice, at 0, 1, 4, 7, and 14 days of a specific diet with different biotin concentrations. Biotin was used at 0.0, 1.8 or 98.2 mg per kg of food;and was referred to as biotin deficient, sufficient and supplemented, respectively. Water and food supply and consumption by the three groups of mice were the same. Therefore, the observed effects were directly related to biotin ingestion. The body weight of biotin supplemented mice was the same as the body weight of mice in the biotin sufficient group, while biotin deficiency caused body weight reduction after 7 days of biotin depletion. We found that the total protein concentration in the vastus lateralis muscle is associated with the biotin content in the diet. After 7 days, the muscle total protein content was lower in mice of the biotin deficient group while it was higher in the mice from the biotin supplemented group展开更多
: Spraying a 1–2 mmol/L solution of NaHSO3 on the leaves of wild-type rice (Oryza sativa L.) Kitaake (WT), phosphoenolpyruvate carboxylase (PEPC) transgenic (PC) rice and PEPC+phosphate dikinase (PPDK) transgenic ric...: Spraying a 1–2 mmol/L solution of NaHSO3 on the leaves of wild-type rice (Oryza sativa L.) Kitaake (WT), phosphoenolpyruvate carboxylase (PEPC) transgenic (PC) rice and PEPC+phosphate dikinase (PPDK) transgenic rice (PC+PK), in which the germplasm was transformed with wild-type Kitaake as the gene receptor, resulted in an enhancement of the net photosynthetic rate by 23.0%, 28.8%, and 34.4%, respectively, for more than 3 d. It was also observed that NaHSO3 application caused an increase in the ATP content in leaves. Spraying PMS (a cofactor catalysing the photophosphorylation cycle) and NaHSO3 separately or together on leaves resulted in an increase in photosynthesis with all treatments. There was no additional effect on photosynthetic rate when the mixture was applied, suggesting that the mechanism by which NaHSO3 promotes photosynthesis is similar to the mechanism by which PMS acts and that both of compounds enhanced the supply of ATP. After spraying a solution of NaHSO3 on leaves, compared with the WT Kitaake rice, a greater enhancement of net photosynthetic rate was observed in PEPC transgenic (PC) and PEPC+PPDK transgenic (PC+PK) rice, with the greatest increase being observed in the latter group. Therefore ATP supply may become the limiting factor that concentrates CO2 in rice leaves transformed with an exogenous PEPC gene and exogenous PEPC+PPDK genes.展开更多
To elucidate the photosynthetic physiological characteristics and the physiological inherited traits of rice （Oryza sativa L.） hybrids and their parents, physiological indices of photosynthetic CO2 exchange and chlo...To elucidate the photosynthetic physiological characteristics and the physiological inherited traits of rice （Oryza sativa L.） hybrids and their parents, physiological indices of photosynthetic CO2 exchange and chlorophyll fluorescence parameters were measured in leaves of the maize phosphoenolpyruvate carboxylase （PEPC） transgenic rice as the male parent, sp. japonica rice cv. 9516 as the female parent, and the stable JAAS45 pollen line. The results revealed that the PEPC gene could be stably inherited and trans- ferred from the male parent to the JAAS45 pollen line. Moreover, the JAAS45 pollen line exhibited high levels of PEPC activity, manifesting higher saturated photosynthetic rates, photosynthetic apparent quantum yield （AQY）, photochemical efficiency of photosystem II and photochemical and non-photochemical quenching, which indicated that the JAAS45 pollen line has a high tolerance to photo-inhibition/photooxidation under strong light and high temperature. Furthermore, JAAS45 was confirmed to still be a C3 plant by δ^13C carbon isotope determination and was demonstrated to have a limited photosynthetic C4 microcycle by feeding with exogenous C4 primary products, such as oxaloacetate or malate, or phosphoenolpyruvate. The present study explains the physiological inherited properties of PEPC transgenic rice and provides an expectation for the integration of traditional breeding and biological technology.展开更多
To study the activity of vitamin K-dependent γ-glutamyl carboxylase in patients with calcium oxalate (CaOx) urolithiasis compared with healthy individuals and to assess its relationship to the renal calcium oxalate u...To study the activity of vitamin K-dependent γ-glutamyl carboxylase in patients with calcium oxalate (CaOx) urolithiasis compared with healthy individuals and to assess its relationship to the renal calcium oxalate urolithiasis Methods Renal parenchymas were harvested from urolithic patients and renal tumor patients undergoing nephrectomy The renal carboxylase activity was evaluated as the radioactivity of [ 14 C] labeled sodium bicarbonate in carboxylic reactions in vitro using β-liquid scintillation counting Results Significantly reduced activity of renal vitamin K-dependent γ-glutamyl carboxylase was observed in the urolithic group as compared with normal controls (P<0 01) Conclusion It suggests that the reduced carboxylase activity observed in the urolithic patients may play an important role in the course of renal calcium oxalate urolithiasis展开更多
Lipid and sugar homeostasis is critical for insect development and survival.In this study,we characterized an acetyl coenzyme A carboxylase gene in Blattella germanica(BgACC)that is involved in both lipogenesis and su...Lipid and sugar homeostasis is critical for insect development and survival.In this study,we characterized an acetyl coenzyme A carboxylase gene in Blattella germanica(BgACC)that is involved in both lipogenesis and sugar homeostasis.We found that BgACC was dominantly expressed in the fat body and integument,and was significantly upregulated after molting.Knockdown of BgACC in 5th-instar nymphs did not affect their normal molting to the next nymphal stage,but it caused a lethal phenotype during adult emergence.BgACC-RNA interference(RNAi)significantly downregulated total free fatty acid(FFA)and triacylglycerol(TAG)levels,and also caused a significant decrease of cuticular hydrocarbons(CHCs).Repression of BgACC in adult females affected the development of oocytes and resulted in sterile females,but BgACC-RNAi did not affect the reproductive ability of males.Interestingly,knockdown of BgACC also changed the expression of insulin-like peptide genes(BglLPs),which mimicked a physiological state of high sugar uptake.In addition,BgACC was upregulated when B.germanica were fed on a high sucrose diet,and repression of BgACC upregulated the expression of the glycogen synthase gene(BgGlyS).Moreover,BgACC-RNAi increased the circulating sugar levels and glycogen storage,and a longevity assay suggested that BgACC was important for the survival of B.germanica under conditions of high sucrose uptake.Our results confirm that BgACC is involved in multiple lipid biogenesis and sugar homeostasis processes,which further modulates insect reproduction and sugar tolerance.This study benefits our understanding of the crosstalk between lipid and sugar metabolism.展开更多
The aurea mutant （Su/su）of tobacco is a nuclear mutation found in Nicotiana tobacum Var. John Williams Broadleaf （Su/su）. Under greenhouse conditions and atmosphere CO2 levels, the yellow mutant tobacco （Su/su） ...The aurea mutant （Su/su）of tobacco is a nuclear mutation found in Nicotiana tobacum Var. John Williams Broadleaf （Su/su）. Under greenhouse conditions and atmosphere CO2 levels, the yellow mutant tobacco （Su/su） grows much slower than the dark green wild type （su/su）. Zelitch reported that the yellow mutant has a higher photorespiratory rate and a lower net rate of photosynthesis, compared with the wild type. RuBP carboxylase/oxygenase is a key enzyme in photosynthesis and photorespiration, and the small subunit of the enzyme is nuclear-encoded. This study was designed to examine if the nuclear gene mutation influenced the structure and properties of the enzyme.展开更多
Ribulose-l,5-bisphosphate carboxylase small subunit gene (rbcS) is present with multi-gene family in plant genome. In Glycine max, the rbcS polypeptide (EC4.1.1.39) is encoded by a gene family containing 4-8 members. ...Ribulose-l,5-bisphosphate carboxylase small subunit gene (rbcS) is present with multi-gene family in plant genome. In Glycine max, the rbcS polypeptide (EC4.1.1.39) is encoded by a gene family containing 4-8 members. Three full-length rbcS cDNA clones were isolated and characterized from soybean seedlings, and both of their nucleotide and amino acid sequences showed high similarity. Differential accumulation of the rbcS mRNA was observed among roots, hypocotyls, cotyledons, epicotyls and leaves. The rbcS genes were up-regulated by various external factors such as salicylic acid (SA), salt stress and drought stress. The expression level of rbcS genes after being treated by 2.0 mmol/L SA and0.4% NaCl, respectively, is 2.5-3.0-fold as high as that of control sample. Moreover, soybean rbcS mRNA was accu-mulated with diurnal variation but easily influenced by light and low temperature.展开更多
Ribulose-1, 5-bisphosphate carboxylase/oxygenase ( EC 4.1.1.39 ) ( RuBP carboxylase ) is a bifunctional enzyme which catalyzes both carboxylation and oxygenation of ribulose-1, 5-bisphosphate (RuBP). These reactions a...Ribulose-1, 5-bisphosphate carboxylase/oxygenase ( EC 4.1.1.39 ) ( RuBP carboxylase ) is a bifunctional enzyme which catalyzes both carboxylation and oxygenation of ribulose-1, 5-bisphosphate (RuBP). These reactions are the first step in photosynthetic carbon fixation and photorespiration respectively. Because of its key role in the formation of plant yield, many studies on the structure of active-site and catalytic mechanism of this enzyme have展开更多
基金supported by the National Natural Science Foundation of China(32172879)the National Key Research and Development Program of China(2022YFD1801700 and 2022YFD1800200)the Top-notch Young Talent Supporting Program to Lan He.Additionally,funding was obtained from the Fundamental Research Funds for the Central Universities(2662020DKPY016 and 2262022DKYJ001).
文摘Apicomplexan parasites predominantly generate ATP and lactic acid through glycolysis and anaerobic glucose metabolism,incorporating CO_(2) into glycolysis via a stage-dependent phosphoenolpyruvate carboxylase(PEPC)mechanism.Although the role of PEPC in plant and bacterial carbon fixation is well documented,its function within Babesia remains largely unexplored.This study employs reverse genetics to probe the biological role of PEPC in Babesia gibsoni,noting its conservation across similar protozoa,suggesting a pivotal and conserved biological function.Western blotting and immunofluorescence(IFA)experiments using the BgPEPC-3×Flag strain revealed that the BgPEPC protein has a molecular weight of 105 kDa and localizes predominantly to the cytoplasm.Attempts to knock out the PEPC gene in BgPEPC-3×Flag strains failed under standard media conditions,succeeded only with the addition of 5 mM malate,an upstream metabolite of oxaloacetic acid(OAA).In addition to malate,the downstream metabolite of OAA can also partially compensate for the phenotypic defects caused by PEPC deficiency.This intervention alleviated severe growth deficits,underscoring the critical role of aspartate in the parasite lifecycle.Moreover,metabolic inhibitors such as L-cycloserine and triazamidine,which target aspartate aminotransferase and mitochondrial functions,respectively,demonstrated increased efficacy against BgPEPC knockout strains.The lack of a compensatory response to malic acid supplementation underscores the integral role of BgPEPC in intermediary carbon metabolism and its necessity in providing aspartate as a precursor to pyrimidine synthesis.Collectively,these findings suggest that PEPC could be a potential target for future drug development against B.gibsoni infections.
文摘[ Objective] The aim of this study was to introduce Phosphoenolpyruvate Carboxylase （PEPCase） gene into common wheat Linyou 145. [ Method] With the material of common wheat Linyou 145, Phosphoenolpyruvate Carboxylase （PEPCase） gene was introduced into wheat embryo callus by the agrobacterium-mediated transformation system, and then analyzed through successive selection with selective medium con- taing gygrornycin to detect the gene at the molecular level. [Result] The hyg-resistant plants were obtained, and GUS histochemical staining showed the leaf of resistant plants was stained dark blue. The target bands appeared in PCR analysis. [ Conclusion] Phosphoenolpyruvate Car- boxylase （PEPCase） gene has been primarily introduced into the recipient material.
基金Supported by the Agriculture Science&Technology Achievements Transformation Fund(No.2011GB24910005)the Modern Agricultural-Industry Technology Research Project(No.200903030)+2 种基金the National High Technology Research and Development Program of China(863 Program)(No.2012AA10A406)the Shandong Agriculture Breeding Engineering Biological Resources Innovation of Research Projectthe National"Twelfth Five-Year"Plan for Science&Technology Support(No.2013BAB01B01)
文摘Saccharina japonica is a common macroalga in sublittoral communities of cold seawater environments, and consequently may have highly efficient ribulose-1, 5-bisphosphate carboxylase/ oxygenase （Rubisco） activity for carbon assimilation. In our study, we cloned the full-length Rubisco gene from S.japonica （SJ-rbc）. It contained an open reading frame for a large subunit gene （SJ-rbcL） of 1 467 bp, a small subunit gene （SJ-rbcS） of 420 bp, and a SJ-rbcL/S intergenie spacer of 269 bp. The deduced peptides of SJ-rbcL and SJ-rbcS were 488 and 139 amino acids with theoretical molecular weights and isoelectric points of 53.97 kDa, 5.81 and 15,84 kDa, 4.71, respectively. After induction with 1 mmol/L isopropyl-β-D- thiogalactopyranoside for 5 h and purification by Ni2＋ affinity chromatography, electrophoresis and western blot detection demonstrated successful expression of the 55 kDa SJ-rbcL protein. Real-time quantitative PCR showed that the mRNA levels of SJ-rbcL in gametophytes increased when transferred into normal growth conditions and exhibited diurnal variations： increased expression during the day but suppressed expression at night. This observation implied that Rubisco played a role in normal gametophytic growth and development. In juvenile sporophytes, mRNA levels of SJ-rbcL, carbonic anhydrase, Calvin-Benson- Bassham cycle-related enzyme, and chloroplast light-harvesting protein were remarkably increased under continuous light irradiance. Similarly, expression of these genes was up-regulated under blue light irradiance at 350 umol/（m2.s）. Our results indicate that long-term white light and short-term blue light irradiance enhances juvenile sporophytic growth by synergistic effects of various photosynthetic elements.
基金supported by the National High Tech-nology Research and Development Program of China(2006AA10A114)the National Basic Research Program of China (2007CB116212)+1 种基金the Natural Science Fundation of Shangdong Province, China(ZR2009DQ004)the Key Technology Research Project of Qingdao, China (07-1-4-16-nsh)
文摘Phosphoenolpyruvate carboxylase （PEPC） is widely distributed in plants and bacteria, and catalyzes the carboxylation of phosphoenolpyruvate to form oxaloacetate and inorganic phosphate. To investigate the molecular mechanisms of the regulation and control of peanut oil, with the degenerated primers and RACE-PCR approach, five PEPC genes were cloned from peanut, and designated as AhPEPC1, AhPEPC2, AhPEPC3, AhPEPC4, and AhPEPC5, respectively. The structure and phylogenetic analysis of PEPC protein indicated that AhPEPC1-4 genes encoded a typical plant-type PEPC-enzyme, and AhPEPC5 a bacterial-type. By real-time quantitative RT-PCR approach the expression pattern of each gene was detected in various tissues of normal and high oil-content peanut varieties. It was found that there was a lower expression level of AhPEPCs genes except for the AhPEPC2 in high-oil peanut than normal-oil peanut line. The results provide some fundamental information for the further investigation of plant PEPC proteins and their role in regulation of oil-content in peanut seeds.
基金supported by the China Agriculture Research System (CARS-14)the National Natural Science Foundation of China (31000728,31100205)+2 种基金the Natural Science Fundation of Shangdong Province,China(ZR2009DQ004,ZR2011CQ036)the Promotive Research Fund for Young and Middle-Aged Scientisits of Shandong Province,China (BS2010NY023)the Qingdao Municipal Science and Technology Plan Project,China (11-2-4-9-(3)-jch,11-2-3-26-nsh)
文摘Phosphoenolpyruvate carboxylase（PEPC;EC 4.1.1.31） catalyses phosphoenolpyruvate（PEP） to yield oxaloacetate,which is involved in protein biosynthesis.Pyruvate kinase（PK;EC 2.7.1.40） catalyzes PEP to yield pyruvate,which is involved in fatty acid synthesis.In this study,five PEPC genes（AhPEPC1,AhPEPC2,AhPEPC3,AhPEPC4,and AhPEPC5） from peanut have been cloned.Using a quantitative real-time RT-PCR approach,the expression pattern of each gene was monitored during the seed development of four peanut varieties（E11,Hebeigaoyou,Naihan 1,and Huayu 26）.It was found that these five genes shared similar expression behaviors over the developmental stages of E11 with high expression levels at 30 and 40 d after pegging（DAP）;whereas these five genes showed irregular expression patterns during the seed development of Hebeigaoyou.In Naihan 1 and Huayu 26,the expression levels of the five genes remained relatively high in the first stage.The PEPC activity was monitored during the seed development of four peanut varieties and seed oil content was also characterized during whole period of seed development.The PEPC activity followed the oil accumulation pattern during the early stages of development but they showed a significantly negative correlation thereafter.These results suggested that PEPC may play an important role in lipid accumulation during the seed development of four peanut varieties tested.
文摘De novo lipogenesis(DNL)plays an important role in the pathogenesis of hepatic steatosis and also appears to be implicated in hepatic inflammation and fibrosis.Accordingly,the inhibition of acetyl-CoA carboxylase,which catalyzes the ratelimiting step of DNL,might represent a useful approach in the management of patients with nonalcoholic fatty liver disease(NAFLD).Animal studies and preliminary data in patients with NAFLD consistently showed an improvement in steatosis with the use of these agents.However,effects on fibrosis were variable and an increase in plasma triglyceride levels was observed.Therefore,more longterm studies are needed to clarify the role of these agents in NAFLD and to determine their risk/benefit profile.
文摘Three F3 hybrids derived from the sterile rice lines Gang 46A, 776A and 2480A and the improved restorer line Shuhui 881 containing maize phosphoenolpyruvate carboxylase （pepc） gene were used to analyze the effect of pepc gene on the heterosis and photosynthetic characteristics, while the F3 obtained by crossing Shuhui 881 with the above three sterile lines served as controls. The dynamics of photosynthetic characteristics in leaves of three F1 with pepc gene and their controls were determined at the initial-tillering, maxium-tillering, elongation, initial-heading, heading, maturity stages, and other different times after flag leaf fully expanded. The PEPCase activities of the three F1 with pepc gene increased significantly as compared with control plants during the whole developmental stages. Moreover, the net photosynthesis rate （Pn） also increased to certain extent. The data showed that PEPCase activity was significantly correlated to Pn with a correlation coefficient of 0.6081. The photosynthetic indexes of the three F1 with pepc gene were obviously superior to respective controls in apparent quantum efficiency, light compensation point and carboxylation efficiency, while the CO2 compensation point was lower than that of corresponding control. The Pn of the three F1 with pepc gene at light saturation point and CO2 saturation point was also higher than that of control plants. in addition, the three F1 with pepc gene had an average increase of 37.10% in grain yields per plant in comparison with control plants. The results indicated that the photosynthetic characteristics of hybrid rice containing pepc gene had been improved to some extent due to the introduction of pepc gene.
文摘To investigate the exon mutation of vitamin K-dependent gamma-glutamyl carboxylase （GGCX or VKDC） in patients with calcium oxalate urolithasis, renal cortex and peripheral blood samples were obtained from severe hydronephrosis patients （with or without calculi）, and renal tumor patients undergoing nephrectomy. GGCX mutations in all 15 exons were examined in 44 patients with calcium oxalate urolithiasis （COU） by polymerase chain reaction （PCR） and denatured high pressure liquid chromatography （DHPLC）, and confirmed by sequencing. Mutation was not found in all COU samples compared to the controls. These data demonstrated that functional GGCX mutations in all 15 exons do not occur in most COU patients. It was suggested that there may be no significant association between the low activity and mutation of GGCX in COU.
基金Supported by the National Natural Science Foundation of China(Nos. 20432010, 20672045 and 30570405)
文摘The entire gene of carboxyltransferase（CT） domain of acetyl-CoA carboxylase（ACCase） from Chinese Spring wheat（CSW） plastid was cloned firstly, and the 2.3 kb gene was inserted into PET28a^＋ vector and expressed in E. coil in a soluble state. The （His）6 fusion protein was identified by SDS-PAGE and Western blot. The recombinant protein was purified by affinity chromatography, and the calculated molecular mass（Mr） was 88000. The results of the sequence analysis indicate that the cloned gene（GeneBank accession No. EU124675） was a supplement and revision of the reported ACCase CT partial cDNA from Chinese Spring wheat plastid. The recombinant protein will be significant for us to investigate the recognizing mechanism between ACCase and herbicides, and further to screen new herbicides.
文摘This study was conducted using seeds in Petri dish containing agar medium in order to determine acetyl-CoA carboxylase （ACCase） herbicides resistance （R） in Avena sterilis that was grown in wheat fields at Adana province, Turkey. Seeds were collected from one large suspected field, where clodinafop-propargyl （Aryloxyphenoxypropionate “FOPs”） and pinoxaden （Phenylpyrazoline “DEN”） have been applied for many years. Susceptible （S） population was collected from the road side on the same region. Agar media of concentration 14 g/L was prepared and it was melted in microwave. Then the amount of 20 mL agar media was added into each Petri dish. Five seeds were placed on agar mediums containing discriminating dose of clodinafop and pinoxaden. Petri dishes were placed in growth incubator operating at 10 °C. After 15 d, both radicle and hypocotyl length were measured. The percentage of germinated seed and dose-response curves were determined. At these different concentration levels, there were more than 50% of R and less than 40% of S seed germinated for pinoxaden. However, for clodinafop, more than 60% of R and less than 50% of S seeds were germinated. At higher concentration levels, the populations of resistant and susceptible were not germinated for both herbicides. The resistance value of R population was then compared with that of the S biotype. From the resistance index （RI）, the population was more resistant to pinoxaden （7.43 for radicle and 2.47 for hypocotyl） than the clodinafop-propagyl （1.39 for radicle and 3.77 for hypocotyl）. The method provided a simple, quick and cost effective way to identify ACCase herbicides resistance in most grass weeds.
文摘Wheat seed storage protein is of great importance for human food. To increase the contents of storage proteins effectively, nitrogen fertilizer at flowering stages is commonly applied. In our previous study, rice phosphoenolpyruvate carboxylase (PEPCase) activity in developing seeds was observed in response to nitrogen application at a flowering stage and was positively correlated to the response of the protein content in seeds of six cultivars. This observation might indicate that the seeds have a biological system for accepting nitrogen in seeds by using PEPCase. To test whether this physiological event occurs in wheat, we examined the PEPCase activity and protein content in field-grown wheat seeds under different nitrogen supply conditions. With only basal dressing, seeds showed lower PEPCase activity and protein content (both 0.90-fold) compared to seeds without basal fertilizer. With ammonium sulfate application at 8.3 and 25 g/m2 at a flowering stage, seeds showed higher PEPCase activity (1.08- and 1.17-fold, respectively) and protein content (1.15- and 1.42-fold, respectively), depending on the nitrogen level. We investigated the relationship between PEPCase activity and protein content in the seeds among four conditions. The effect of the nitrogen supply on PEPCase activity during grain-filling stages was validated by the results of a hydroponic culture experiment. Together the results demonstrate that our hypothesis seems to apply to field-grown wheat.
基金supported by a grant from the Direccion General de Asuntos del Personal Academico(DGAPA),Universidad Nacional Autonoma de Mexico(PAPIIT IN215311).MA P MdeO was fellow of DGAPA.
文摘In mammalian skeletal muscle there are four carboxylases involved in several biochemical processes like gluconeogenesis, tricarboxylic acid cycle anaplerosis, metabolism of fatty acids and metabolism of various amino acids. It has been shown that biotin deficiency reduces body weight at the expense of muscular mass. When necessary, the liver uses skeletal muscle protein to provide glucose and amino acids to organs in need of such compounds. In this paper we analyzed carboxylase specific activities in hind limb skeletal muscle of 3 weeks old BALB/c male mice, at 0, 1, 4, 7, and 14 days of a specific diet with different biotin concentrations. Biotin was used at 0.0, 1.8 or 98.2 mg per kg of food;and was referred to as biotin deficient, sufficient and supplemented, respectively. Water and food supply and consumption by the three groups of mice were the same. Therefore, the observed effects were directly related to biotin ingestion. The body weight of biotin supplemented mice was the same as the body weight of mice in the biotin sufficient group, while biotin deficiency caused body weight reduction after 7 days of biotin depletion. We found that the total protein concentration in the vastus lateralis muscle is associated with the biotin content in the diet. After 7 days, the muscle total protein content was lower in mice of the biotin deficient group while it was higher in the mice from the biotin supplemented group
基金国家自然科学基金，the National Key Project of the International Cooperation for Science and Technology
文摘: Spraying a 1–2 mmol/L solution of NaHSO3 on the leaves of wild-type rice (Oryza sativa L.) Kitaake (WT), phosphoenolpyruvate carboxylase (PEPC) transgenic (PC) rice and PEPC+phosphate dikinase (PPDK) transgenic rice (PC+PK), in which the germplasm was transformed with wild-type Kitaake as the gene receptor, resulted in an enhancement of the net photosynthetic rate by 23.0%, 28.8%, and 34.4%, respectively, for more than 3 d. It was also observed that NaHSO3 application caused an increase in the ATP content in leaves. Spraying PMS (a cofactor catalysing the photophosphorylation cycle) and NaHSO3 separately or together on leaves resulted in an increase in photosynthesis with all treatments. There was no additional effect on photosynthetic rate when the mixture was applied, suggesting that the mechanism by which NaHSO3 promotes photosynthesis is similar to the mechanism by which PMS acts and that both of compounds enhanced the supply of ATP. After spraying a solution of NaHSO3 on leaves, compared with the WT Kitaake rice, a greater enhancement of net photosynthetic rate was observed in PEPC transgenic (PC) and PEPC+PPDK transgenic (PC+PK) rice, with the greatest increase being observed in the latter group. Therefore ATP supply may become the limiting factor that concentrates CO2 in rice leaves transformed with an exogenous PEPC gene and exogenous PEPC+PPDK genes.
基金Supported by the National Natural Science Foundation of China （30571119）, Sichuan Science and Technology Foundation （047Q026-036）, and Program for New Century Excellent Talents in University （NCET-05-0786）.
文摘To elucidate the photosynthetic physiological characteristics and the physiological inherited traits of rice （Oryza sativa L.） hybrids and their parents, physiological indices of photosynthetic CO2 exchange and chlorophyll fluorescence parameters were measured in leaves of the maize phosphoenolpyruvate carboxylase （PEPC） transgenic rice as the male parent, sp. japonica rice cv. 9516 as the female parent, and the stable JAAS45 pollen line. The results revealed that the PEPC gene could be stably inherited and trans- ferred from the male parent to the JAAS45 pollen line. Moreover, the JAAS45 pollen line exhibited high levels of PEPC activity, manifesting higher saturated photosynthetic rates, photosynthetic apparent quantum yield （AQY）, photochemical efficiency of photosystem II and photochemical and non-photochemical quenching, which indicated that the JAAS45 pollen line has a high tolerance to photo-inhibition/photooxidation under strong light and high temperature. Furthermore, JAAS45 was confirmed to still be a C3 plant by δ^13C carbon isotope determination and was demonstrated to have a limited photosynthetic C4 microcycle by feeding with exogenous C4 primary products, such as oxaloacetate or malate, or phosphoenolpyruvate. The present study explains the physiological inherited properties of PEPC transgenic rice and provides an expectation for the integration of traditional breeding and biological technology.
基金TheworkwassupportedbyagrantfromtheNationalNaturalScienceFoundationofChina (No .3990 70 740 )
文摘To study the activity of vitamin K-dependent γ-glutamyl carboxylase in patients with calcium oxalate (CaOx) urolithiasis compared with healthy individuals and to assess its relationship to the renal calcium oxalate urolithiasis Methods Renal parenchymas were harvested from urolithic patients and renal tumor patients undergoing nephrectomy The renal carboxylase activity was evaluated as the radioactivity of [ 14 C] labeled sodium bicarbonate in carboxylic reactions in vitro using β-liquid scintillation counting Results Significantly reduced activity of renal vitamin K-dependent γ-glutamyl carboxylase was observed in the urolithic group as compared with normal controls (P<0 01) Conclusion It suggests that the reduced carboxylase activity observed in the urolithic patients may play an important role in the course of renal calcium oxalate urolithiasis
基金funded by the National Natural Science Foundation of China(32200384)the China Postdoctoral Science Foundation(2022M710053).
文摘Lipid and sugar homeostasis is critical for insect development and survival.In this study,we characterized an acetyl coenzyme A carboxylase gene in Blattella germanica(BgACC)that is involved in both lipogenesis and sugar homeostasis.We found that BgACC was dominantly expressed in the fat body and integument,and was significantly upregulated after molting.Knockdown of BgACC in 5th-instar nymphs did not affect their normal molting to the next nymphal stage,but it caused a lethal phenotype during adult emergence.BgACC-RNA interference(RNAi)significantly downregulated total free fatty acid(FFA)and triacylglycerol(TAG)levels,and also caused a significant decrease of cuticular hydrocarbons(CHCs).Repression of BgACC in adult females affected the development of oocytes and resulted in sterile females,but BgACC-RNAi did not affect the reproductive ability of males.Interestingly,knockdown of BgACC also changed the expression of insulin-like peptide genes(BglLPs),which mimicked a physiological state of high sugar uptake.In addition,BgACC was upregulated when B.germanica were fed on a high sucrose diet,and repression of BgACC upregulated the expression of the glycogen synthase gene(BgGlyS).Moreover,BgACC-RNAi increased the circulating sugar levels and glycogen storage,and a longevity assay suggested that BgACC was important for the survival of B.germanica under conditions of high sucrose uptake.Our results confirm that BgACC is involved in multiple lipid biogenesis and sugar homeostasis processes,which further modulates insect reproduction and sugar tolerance.This study benefits our understanding of the crosstalk between lipid and sugar metabolism.
文摘The aurea mutant （Su/su）of tobacco is a nuclear mutation found in Nicotiana tobacum Var. John Williams Broadleaf （Su/su）. Under greenhouse conditions and atmosphere CO2 levels, the yellow mutant tobacco （Su/su） grows much slower than the dark green wild type （su/su）. Zelitch reported that the yellow mutant has a higher photorespiratory rate and a lower net rate of photosynthesis, compared with the wild type. RuBP carboxylase/oxygenase is a key enzyme in photosynthesis and photorespiration, and the small subunit of the enzyme is nuclear-encoded. This study was designed to examine if the nuclear gene mutation influenced the structure and properties of the enzyme.
基金This work was supported by the National Key Basic Research Special Funds of China (Grant No. G1998010209).
文摘Ribulose-l,5-bisphosphate carboxylase small subunit gene (rbcS) is present with multi-gene family in plant genome. In Glycine max, the rbcS polypeptide (EC4.1.1.39) is encoded by a gene family containing 4-8 members. Three full-length rbcS cDNA clones were isolated and characterized from soybean seedlings, and both of their nucleotide and amino acid sequences showed high similarity. Differential accumulation of the rbcS mRNA was observed among roots, hypocotyls, cotyledons, epicotyls and leaves. The rbcS genes were up-regulated by various external factors such as salicylic acid (SA), salt stress and drought stress. The expression level of rbcS genes after being treated by 2.0 mmol/L SA and0.4% NaCl, respectively, is 2.5-3.0-fold as high as that of control sample. Moreover, soybean rbcS mRNA was accu-mulated with diurnal variation but easily influenced by light and low temperature.
文摘Ribulose-1, 5-bisphosphate carboxylase/oxygenase ( EC 4.1.1.39 ) ( RuBP carboxylase ) is a bifunctional enzyme which catalyzes both carboxylation and oxygenation of ribulose-1, 5-bisphosphate (RuBP). These reactions are the first step in photosynthetic carbon fixation and photorespiration respectively. Because of its key role in the formation of plant yield, many studies on the structure of active-site and catalytic mechanism of this enzyme have
