Carbon Fluxes in Potato () Remain Stable in Cell Cultures Exposed to Nutritional Phosphate Deficiency.

Nutritional phosphate deficiency is a major limitation to plant growth. Here, we monitored fluxes in pathways supporting respiratory metabolism in potato () cell cultures growing in control or limiting phosphate conditions. Sugar uptake was quantified using [U-C]sucrose as precursor.

Pseudophosphorylation of Arabidopsis jasmonate biosynthesis enzyme lipoxygenase 2 via mutation of Ser inhibits enzyme activity.

Jasmonates are oxylipin phytohormones critical for plant resistance against necrotrophic pathogens and chewing herbivores. An early step in their biosynthesis is catalyzed by non-heme iron lipoxygenases (LOX; EC 1.13.

Orchestrated translation specializes dinoflagellate metabolism three times per day.

Many cells specialize for different metabolic tasks at different times over their normal ZT cycle by changes in gene expression. However, in most cases, circadian gene expression has been assessed at the mRNA accumulation level, which may not faithfully reflect protein synthesis rates. Here, we use ribosome profiling in the dinoflagellate to identify thousands of transcripts showing coordinated translation.

Glutathione Metabolism in Plants under Stress: Beyond Reactive Oxygen Species Detoxification.

Glutathione is an essential metabolite for plant life best known for its role in the control of reactive oxygen species (ROS). Glutathione is also involved in the detoxification of methylglyoxal (MG) which, much like ROS, is produced at low levels by aerobic metabolism under normal conditions. While several physiological processes depend on ROS and MG, a variety of stresses can dramatically increase their concentration leading to potentially deleterious effects.

Phycobilin heterologous production from the Rhodophyta Porphyridium cruentum.

Phycobiliproteins are colored, active molecules with potential use in different industries. They are the union of proteins and bilins (Chromophores). The primary source of phycobiliproteins is algae; however, the traditional algae culture has production restrictions.

A Diacylglycerol Kinase Inhibitor, R-59-022, Blocks Filovirus Internalization in Host Cells.

Filoviruses, such as Ebola virus (EBOV) and Marburg virus, are causative agents of unpredictable outbreaks of severe hemorrhagic fevers in humans and non-human primates. For infection, filoviral particles need to be internalized and delivered to intracellular vesicles containing cathepsin proteases and the viral receptor Niemann-Pick C1. Previous studies have shown that EBOV triggers macropinocytosis of the viral particles in a glycoprotein (GP)-dependent manner, but the molecular events required for filovirus internalization remain mostly unknown.

Sustained substrate cycles between hexose phosphates and free sugars in phosphate-deficient potato (Solanum tuberosum) cell cultures.

Futile cycling between free sugars and hexose phosphates occurring under phosphate deficiency could be involved in the maintenance of a threshold level of free cellular phosphate to preserve respiratory metabolism. We studied the metabolic response of potato cell cultures growing in Pi sufficient (2.5 mM, +Pi) or deficient (125 µM, -Pi) conditions.

Plant nucleoside diphosphate kinase 1: A housekeeping enzyme with moonlighting activity.

Nucleoside diphosphate kinase (NDPK) catalyzes the interconversion of nucleoside diphosphates and triphosphates using ATP as phosphate donor. This housekeeping enzyme is present in several subcellular compartments. The main isoform (NDPK1) is located in the cytosol and is highly expressed in meristems and provascular tissues.

Molecular and biochemical characterization of the sunflower (Helianthus annuus L.) cytosolic and plastidial enolases in relation to seed development.

In the present study, we describe the molecular and biochemical characterization of sunflower (Helianthus annuus L.) enolase (ENO, EC 4.2.

Cytosolic Triosephosphate Isomerase from Is Reversibly Modified by Glutathione on Cysteines 127 and 218.

In plant cells, an increase in cellular oxidants can have multiple effects, including the promotion of mixed disulfide bonds between glutathione and some proteins (-glutathionylation). The present study focuses on the cytosolic isoform of the glycolytic enzyme triosephosphate isomerase (cTPI) from and its reversible modification by glutathione. We used purified recombinant cTPI to demonstrate the enzyme sensitivity to inhibition by -ethylmaleimide, hydrogen peroxide and diamide.

Engineering the expression level of cytosolic nucleoside diphosphate kinase in transgenic Solanum tuberosum roots alters growth, respiration and carbon metabolism.

Nucleoside diphosphate kinase (NDPK) is a ubiquitous enzyme that catalyzes the transfer of the γ-phosphate from a donor nucleoside triphosphate to an acceptor nucleoside diphosphate. In this study we used a targeted metabolomic approach and measurement of physiological parameters to report the effects of the genetic manipulation of cytosolic NDPK (NDPK1) expression on physiology and carbon metabolism in potato (Solanum tuberosum) roots. Sense and antisense NDPK1 constructs were introduced in potato using Agrobacterium rhizogenes to generate a population of root clones displaying a 40-fold difference in NDPK activity.

The Plant Ovule Secretome: A Different View toward Pollen-Pistil Interactions.

During plant sexual reproduction, continuous exchange of signals between the pollen and the pistil (stigma, style, and ovary) plays important roles in pollen recognition and selection, establishing breeding barriers and, ultimately, leading to optimal seed set. After navigating through the stigma and the style, pollen tubes (PTs) reach their final destination, the ovule. This ultimate step is also regulated by numerous signals emanating from the embryo sac (ES) of the ovule.

Expression, purification and characterization of Solanum tuberosum recombinant cytosolic pyruvate kinase.

The cDNA encoding for a Solanum tuberosum cytosolic pyruvate kinase 1 (PKc1) highly expressed in tuber tissue was cloned in the bacterial expression vector pProEX HTc. The construct carried a hexahistidine tag in N-terminal position to facilitate purification of the recombinant protein. Production of high levels of soluble recombinant PKc1 in Escherichia coli was only possible when using a co-expression strategy with the chaperones GroES-GroEL.

The dinoflagellate Lingulodinium polyedrum responds to N depletion by a polarized deposition of starch and lipid bodies.

Dinoflagellates are important contributors to the marine phytoplankton and global carbon fixation, but are also infamous for their ability to form the spectacular harmful algal blooms called red tides. While blooms are often associated with high available nitrogen, there are instances where they are observed in oligotrophic environments. In order to maintain their massive population in conditions of nitrogen limitation, dinoflagellates must have evolved efficient adaptive mechanisms.

Clues to the functions of plant NDPK isoforms.

This review describes the five nucleoside diphosphate kinase (NDPK) genes found in both model plants Arabidopsis thaliana (thale cress) and Oryza sativa L. (rice). Phylogenetic and sequence analyses of these genes allow the definition of four types of NDPK isoforms with different predicted subcellular localization.

The futile cycling of hexose phosphates could account for the fact that hexokinase exerts a high control on glucose phosphorylation but not on glycolytic rate in transgenic potato (Solanum tuberosum) roots.

The metabolism of potato (Solanum tuberosum) roots constitutively over- and underexpressing hexokinase (HK, EC 2.7.1.

A large decrease of cytosolic triosephosphate isomerase in transgenic potato roots affects the distribution of carbon in primary metabolism.

Triosephosphate isomerase (TPI, EC 5.3.1.

Molecular cloning and biochemical characterization of three phosphoglycerate kinase isoforms from developing sunflower (Helianthus annuus L.) seeds.

Three cDNAs encoding different phosphoglycerate kinase (PGK, EC 2.7.2.

Cloning, biochemical characterization and expression of a sunflower (Helianthus annuus L.) hexokinase associated with seed storage compounds accumulation.

A full-length hexokinase cDNA, HaHXK1, was cloned and characterized from Helianthus annuus L. developing seeds. Based on its sequence and phylogenetic relationships, HaHXK1 is a membrane-associated (type-B) hexokinase.

Cloning, biochemical characterisation, tissue localisation and possible post-translational regulatory mechanism of the cytosolic phosphoglucose isomerase from developing sunflower seeds.

Lipid biosynthesis in developing sunflower (Helianthus annuus L.) seeds requires reducing power. One of the main sources of cellular NADPH is the oxidative pentose phosphate pathway (OPPP), generated from the oxidation of glucose-6-phosphate.

Non-nutritive swallowing and respiration coordination among states of alertness in adult sheep.

Swallowing is a powerful inhibitor of respiration. Its coordination with respiration is therefore crucial to avoid aspiration and apnea. The aim of this study was to determine the coordination between non-nutritive swallowing (NNS) and phases of the respiratory cycle, including the assessment of the effect of states of alertness in adult sheep.

Autophosphorylation of Solanum chacoense cytosolic nucleoside diphosphate kinase on Ser117.

NDPK catalyses the interconversion of NTPs and NDPs using a phosphohistidine intermediate as part of its catalytic site. Recombinant Solanum chacoense cytosolic NDPK incubated with [gamma-(32)P]ATP was allowed to autophosphorylate and (32)P-labelled P-Ser was identified in an acid hydrolysate of the protein by two-dimensional TLC. Further analysis of (32)P-labelled recombinant NDPK by tryptic digestion followed by automated Edman sequencing of the radioactive peptide allowed the identification of a single and conserved P-Ser residue at position 117.

Characterization of a cytosolic nucleoside diphosphate kinase associated with cell division and growth in potato.

A cDNA encoding Solanum chacoense cytosolic NDPK (NDPK1, EC 2.7.4.

Quantification of uridine 5'-diphosphate (UDP)-glucose by high-performance liquid chromatography and its application to a nonradioactive assay for nucleoside diphosphate kinase using UDP-glucose pyrophosphorylase as a coupling enzyme.

We describe a method for the detection and quantification of nucleoside diphosphate kinase (NDPK). NDPK catalyzes the transfer of the gamma-phosphate of cytidine 5'-triphosphate on uridine 5'-diphosphate (UDP) to produce uridine 5'-triphosphate (UTP). The method uses a nonradioactive coupled enzyme assay in which UTP produced by NDPK is utilized by UDP-glucose pyrophosphorylase.