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.

scholarly journals The role of malate in the synthesis of glutamate in Pisum arvense roots

2014 ◽  
Vol 55 (4) ◽  
pp. 611-619
Author(s):  
Genowefa Kubik-Dorosz
Keyword(s):  
Glutamic Acid ◽  
Malic Acid ◽  
Glutamate Synthase ◽  
Acid Synthesis ◽  
Incubation Mixture ◽  
Pyridine Nucleotides ◽  
Pisum Arvense

The in vivo and in vitro activities of NADH-dependent glutamate synthase in excised <em>Pisum arvense</em> roots increased several-fold under the influence of malate while pyruvate oxaloacctate. citrate and succinate inhibited this entyme. The plastids isolated from <em>Pisum arvense</em> root,. ahen incubated with glutamine and α-ketoglutarate, released glutamate into the medium Malate clearly stimulated this process. Albizziin (25 mM) completely reduced the presence of glutamate in the incubation mixture. These results indicate that reduced pyridine nucleotides arising in <em>P. arvense</em> root plastids during oxidation of malic acid may constitute the indispensable source of electrons for glutamic acid synthesis.

scholarly journals Post-translational Regulation of DNA Polymerase η, a Connection to Damage-Induced Cohesion in Saccharomyces cerevisiae

Genetics ◽  
2020 ◽  
Vol 216 (4) ◽  
pp. 1009-1022 ◽  
Author(s):  
Pei-Shang Wu ◽  
Elin Enervald ◽  
Angelica Joelsson ◽  
Carina Palmberg ◽  
Dorothea Rutishauser ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ultraviolet Irradiation ◽  
Protein Level ◽  
Phosphorylation Site ◽  
Nuclear Accumulation ◽  
Link Type ◽  
Genome Wide ◽  
Break Site

Double-strand breaks that are induced postreplication trigger establishment of damage-induced cohesion in Saccharomyces cerevisiae, locally at the break site and genome-wide on undamaged chromosomes. The translesion synthesis polymerase, polymerase η, is required for generation of damage-induced cohesion genome-wide. However, its precise role and regulation in this process is unclear. Here, we investigated the possibility that the cyclin-dependent kinase Cdc28 and the acetyltransferase Eco1 modulate polymerase η activity. Through in vitro phosphorylation and structure modeling, we showed that polymerase η is an attractive substrate for Cdc28. Mutation of the putative Cdc28-phosphorylation site Ser14 to Ala not only affected polymerase η protein level, but also prevented generation of damage-induced cohesion in vivo. We also demonstrated that Eco1 acetylated polymerase η in vitro. Certain nonacetylatable polymerase η mutants showed reduced protein level, deficient nuclear accumulation, and increased ultraviolet irradiation sensitivity. In addition, we found that both Eco1 and subunits of the cohesin network are required for cell survival after ultraviolet irradiation. Our findings support functionally important Cdc28-mediated phosphorylation, as well as post-translational modifications of multiple lysine residues that modulate polymerase η activity, and provide new insights into understanding the regulation of polymerase η for damage-induced cohesion.

scholarly journals E3 ubiquitin ligase Grail promotes hepatic steatosis through Sirt1 inhibition

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Pei-Yao Liu ◽  
Cheng-Cheung Chen ◽  
Chia-Ying Chin ◽  
Te-Jung Liu ◽  
Wen-Chiuan Tsai ◽  
...  
Keyword(s):  
Hepatic Steatosis ◽  
Lipid Accumulation ◽  
Acid Synthesis ◽  
Sirtuin 1 ◽  
Nonalcoholic Fatty Liver ◽  
Expression Of Genes ◽  
Hepatic Fat ◽  
Underlying Mechanisms

AbstractIn obese adults, nonalcoholic fatty liver disease (NAFLD) is accompanied by multiple metabolic dysfunctions. Although upregulated hepatic fatty acid synthesis has been identified as a crucial mediator of NAFLD development, the underlying mechanisms are yet to be elucidated. In this study, we reported upregulated expression of gene related to anergy in lymphocytes (GRAIL) in the livers of humans and mice with hepatic steatosis. Grail ablation markedly alleviated the high-fat diet-induced hepatic fat accumulation and expression of genes related to the lipid metabolism, in vitro and in vivo. Conversely, overexpression of GRAIL exacerbated lipid accumulation and enhanced the expression of lipid metabolic genes in mice and liver cells. Our results demonstrated that Grail regulated the lipid accumulation in hepatic steatosis via interaction with sirtuin 1. Thus, Grail poses as a significant molecular regulator in the development of NAFLD.

scholarly journals Phosphorylation of Serine 303 Is a Prerequisite for the Stress-Inducible SUMO Modification of Heat Shock Factor 1

2003 ◽  
Vol 23 (8) ◽  
pp. 2953-2968 ◽  
Author(s):  
Ville Hietakangas ◽  
Johanna K. Ahlskog ◽  
Annika M. Jakobsson ◽  
Maria Hellesuo ◽  
Niko M. Sahlberg ◽  
...  
Keyword(s):  
Heat Shock ◽  
Phosphorylation Site ◽  
Stress Granules ◽  
Heat Shock Factor ◽  
Transcriptional Level ◽  
Heat Shock Factor 1 ◽  
Protection Mechanism ◽  
Sumo Modification

ABSTRACT The heat shock response, which is accompanied by a rapid and robust upregulation of heat shock proteins (Hsps), is a highly conserved protection mechanism against protein-damaging stress. Hsp induction is mainly regulated at transcriptional level by stress-inducible heat shock factor 1 (HSF1). Upon activation, HSF1 trimerizes, binds to DNA, concentrates in the nuclear stress granules, and undergoes a marked multisite phosphorylation, which correlates with its transcriptional activity. In this study, we show that HSF1 is modified by SUMO-1 and SUMO-2 in a stress-inducible manner. Sumoylation is rapidly and transiently enhanced on lysine 298, located in the regulatory domain of HSF1, adjacent to several critical phosphorylation sites. Sumoylation analyses of HSF1 phosphorylation site mutants reveal that specifically the phosphorylation-deficient S303 mutant remains devoid of SUMO modification in vivo and the mutant mimicking phosphorylation of S303 promotes HSF1 sumoylation in vitro, indicating that S303 phosphorylation is required for K298 sumoylation. This finding is further supported by phosphopeptide mapping and analysis with S303/7 phosphospecific antibodies, which demonstrate that serine 303 is a target for strong heat-inducible phosphorylation, corresponding to the inducible HSF1 sumoylation. A transient phosphorylation-dependent colocalization of HSF1 and SUMO-1 in nuclear stress granules provides evidence for a strictly regulated subnuclear interplay between HSF1 and SUMO.

scholarly journals Regulation of GABAergic synapse formation and plasticity by GSK3β-dependent phosphorylation of gephyrin

2010 ◽  
Vol 108 (1) ◽  
pp. 379-384 ◽  
Author(s):  
Shiva K. Tyagarajan ◽  
Himanish Ghosh ◽  
Gonzalo E. Yévenes ◽  
Irina Nikonenko ◽  
Claire Ebeling ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Hippocampal Neurons ◽  
Glycogen Synthase ◽  
Phosphorylation Site ◽  
Scaffolding Protein ◽  
Scaffolding Proteins ◽  
Gabaergic Synapse ◽  
Gabaergic Synapses

Postsynaptic scaffolding proteins ensure efficient neurotransmission by anchoring receptors and signaling molecules in synapse-specific subcellular domains. In turn, posttranslational modifications of scaffolding proteins contribute to synaptic plasticity by remodeling the postsynaptic apparatus. Though these mechanisms are operant in glutamatergic synapses, little is known about regulation of GABAergic synapses, which mediate inhibitory transmission in the CNS. Here, we focused on gephyrin, the main scaffolding protein of GABAergic synapses. We identify a unique phosphorylation site in gephyrin, Ser270, targeted by glycogen synthase kinase 3β (GSK3β) to modulate GABAergic transmission. Abolishing Ser270 phosphorylation increased the density of gephyrin clusters and the frequency of miniature GABAergic postsynaptic currents in cultured hippocampal neurons. Enhanced, phosphorylation-dependent gephyrin clustering was also induced in vitro and in vivo with lithium chloride. Lithium is a GSK3β inhibitor used therapeutically as mood-stabilizing drug, which underscores the relevance of this posttranslational modification for synaptic plasticity. Conversely, we show that gephyrin availability for postsynaptic clustering is limited by Ca2+-dependent gephyrin cleavage by the cysteine protease calpain-1. Together, these findings identify gephyrin as synaptogenic molecule regulating GABAergic synaptic plasticity, likely contributing to the therapeutic action of lithium.

scholarly journals Characterization and Expression Analysis of Genes Encoding Phosphoenolpyruvate Carboxylase and Phosphoenolpyruvate Carboxylase Kinase of Lotus japonicus, a Model Legume

2003 ◽  
Vol 16 (4) ◽  
pp. 281-288 ◽  
Author(s):  
Tomomi Nakagawa ◽  
Tomoko Izumi ◽  
Mari Banba ◽  
Yosuke Umehara ◽  
Hiroshi Kouchi ◽  
...  
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Root Nodules ◽  
Expression Patterns ◽  
Phosphorylation Site ◽  
Lotus Japonicus ◽  
Specific Protein ◽  
Mrna Levels ◽  
Model Legume ◽  
Putative Phosphorylation Site

Phosphoenolpyruvate carboxylases (PEPCs), one form of which in each legume species plays a central role in the carbon metabolism in symbiotic root nodules, are activated through phosphorylation of a conserved residue by a specific protein kinase (PEPC-PK). We characterized the cDNAs for two PEPC isoforms of Lotus japonicus, an amide-translocating legume that forms determinate nodules. One gene encodes a nodule-enhanced form, which is more closely related to the PEPCs in amide-type indeterminate nodules than those in ureide-type determinate nodules. The other gene is expressed in shoots and roots at a low level. Both forms have the putative phosphorylation site, Ser11. We also isolated a cDNA and the corresponding genomic DNA for PEPC-PK of L. japonicus. The recombinant PEPC-PK protein expressed in Escherichia coli phosphorylated recombinant maize C4-form PEPC efficiently in vitro. The level of mRNA for PEPC-PK was high in root nodules, and those in shoots and roots were also significant. In situ hybridization revealed that the expression patterns of the transcripts for PEPC and PEPC-PK were similar in mature root nodules, but were different in emerging nodules. When L. japonicus seedlings were subjected to prolonged darkness and subsequent illumination, the activity of PEPC-PK and the mRNA levels of both PEPC and PEPC-PK in nodules decreased and then recovered, suggesting that they are regulated according to the amounts of photosynthates transported from shoots.

In vivo and in vitro lipogenesis and aspects of metabolism in ovines: Effect of environmental temperature and dietary lipid supplementation

2000 ◽  
Vol 80 (1) ◽  
pp. 59-67 ◽  
Author(s):  
J. A. Moibi ◽  
R. J. Christopherson ◽  
E. K. Okine
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Cold Exposure ◽  
Average Daily Gain ◽  
Acid Synthesis ◽  
Dietary Lipid ◽  
Acetate Incorporation ◽  
Lipid Supplementation

Twenty-four wether lambs were randomly allocated to six treatments to investigate the effect of temperature and dietary lipid supplements on fatty acid synthesis and metabolic activity in sheep. The treatments consisted of four groups exposed to either cold (0 °C) or warm temperature (+23 °C) and given ad libitum access to either a control barley-based diet or with lipid supplementation. Two other groups were placed on the dietary regimen at 0 °C, but pair-fed to intake of animals in the +23 °C environment. At 5 wk, fatty acid synthesis was measured by [1-14C]acetate incorporation into tissue lipids. Cold exposure and dietary lipid supplementation had no effect (P > 0.05) on in vivo fatty acid synthesis rates in either longissimus dorsi or the liver. In both subcutaneous and mesenteric adipose tissue depots, the rate of acetate incorporation into tissue lipid was not significantly affected by cold exposure. In the perirenal fat depot, cold exposure increased (P < 0.05) the rate of fatty acid synthesis, while lipid supplementation decreased (P < 0.05) the rate in all tissue adipose depots. In vitro, mesenteric and perirenal adipose tissues from cold pair-fed animals had higher (P < 0.05) rates of fatty acid synthesis compared to tissues from animals in the warm environment. However, there was no effect of dietary lipid supplementation in these two fat depots. Metabolic heat production, and energy and nitrogen excretion by animals were increased (P < 0.05) by cold exposure while lipid supplementation had the opposite effect (P < 0.05). The relationship between average daily gain and feed intake was linear at both warm and cold environments, but with higher (P < 0.05) average daily gain at all levels of intake in the cold compared to the warm environment. Results indicate that both environment and diet regulate metabolic activity in sheep. However, there were differences in lipogenic response by tissues to the treatments. Key words: Environmental temperature, dietary lipid, fatty acid synthesis, metabolic rate, sheep

Phosphorylation of caldesmon by ERK MAP kinases in smooth muscle

2000 ◽  
Vol 278 (4) ◽  
pp. C718-C726 ◽  
Author(s):  
Jason C. Hedges ◽  
Brian C. Oxhorn ◽  
Michael Carty ◽  
Leonard P. Adam ◽  
Ilia A. Yamboliev ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Map Kinase ◽  
Map Kinases ◽  
Isometric Force ◽  
Phosphorylation Site ◽  
Smooth Muscle Contraction ◽  
Tracheal Smooth Muscle ◽  
Muscarinic Agonists

Phosphorylation of h-caldesmon has been proposed to regulate airway smooth muscle contraction. Both extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein (MAP) kinases phosphorylate h-caldesmon in vitro. To determine whether both enzymes phosphorylate caldesmon in vivo, phosphorylation-site-selective antibodies were used to assay phosphorylation of MAP kinase consensus sites. Stimulation of cultured tracheal smooth muscle cells with ACh or platelet-derived growth factor increased caldesmon phosphorylation at Ser789 by about twofold. Inhibiting ERK MAP kinase activation with 50 μM PD-98059 blocked agonist-induced caldesmon phosphorylation completely. Inhibiting p38 MAP kinases with 25 μM SB-203580 had no effect on ACh-induced caldesmon phosphorylation. Carbachol stimulation increased caldesmon phosphorylation at Ser789 in intact tracheal smooth muscle, which was blocked by the M2 antagonist AF-DX 116 (1 μM). AF-DX 116 inhibited carbachol-induced isometric contraction by 15 ± 1.4%, thus dissociating caldesmon phosphorylation from contraction. Activation of M2 receptors leads to activation of ERK MAP kinases and phosphorylation of caldesmon with little or no functional effect on isometric force. P38 MAP kinases are also activated by muscarinic agonists, but they do not phosphorylate caldesmon in vivo.

scholarly journals A Protective Role of Paeoniflorin in Fluctuant Hyperglycemia-Induced Vascular Endothelial Injuries through Antioxidative and Anti-Inflammatory Effects and Reduction of PKCβ1

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Jing-Shang Wang ◽  
Ye Huang ◽  
Shuping Zhang ◽  
Hui-Jun Yin ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Protein Level ◽  
Umbilical Vein ◽  
Protective Role ◽  
Vascular Endothelial ◽  
Glucose Levels ◽  
Umbilical Vein Endothelial Cells

Hyperglycemia fluctuation is associated with diabetes mellitus (DM) complications when compared to persistent hyperglycemia. Previous studies have shown that paeoniflorin (PF), through its antiapoptosis, anti-inflammation, and antithrombotic properties, effectively protects against cardiovascular and cerebrovascular disease. However, the mechanism underlying the protection from PF against vascular injuries induced by hyperglycemia fluctuations remains poorly understood. Herein, we investigated the potential protective role of PF on human umbilical vein endothelial cells (HUVECs) subjected to intermittent glucose levels in vitro and in DM rats with fluctuating hyperglycemia in vivo. A remarkable increased apoptosis associated with elevated inflammation, increased oxidative stress, and high protein level of PKCβ1 was induced in HUVECs by intermittently changing glucose for 8 days, and PF recovered those detrimental changes. LY333531, a potent PKCβ1 inhibitor, and metformin manifested similar effects. Additionally, in DM rats with fluctuating hyperglycemia, PF protected against vascular damage as what has been observed in vitro. Taken together, PF attenuates the vascular injury induced by fluctuant hyperglycemia through oxidative stress inhibition, inflammatory reaction reduction, and PKCβ1 protein level repression, suggesting its perspective clinical usage.

scholarly journals Effects of Essential Oils to Control Penicillium Sp. In In Vitro and in In Vivo on Grapevine (Vitis Vinifera L.) Fruit

2020 ◽  
Vol 20 (sup2) ◽  
pp. 812-826
Author(s):  
Mehdi Jahani ◽  
Mahdiyeh Beheshti ◽  
Mohammad Hossein Aminifard ◽  
Atefeh Hosseini
Keyword(s):  
Vitis Vinifera ◽  
Essential Oils ◽  
Vitis Vinifera L ◽  
Penicillium Sp
Sign in / Sign up

Export Citation Format

Share Document