Ion mobility mass spectrometry has become popular in proteomics lately, in particular because the Bruker timsTOF instruments have found significant adoption in proteomics facilities. The Bruker's implementation of the ion mobility dimension generates massive amounts of mass spectrometric data that require carefully designed software both to extract meaningful information and to perform processing tasks at reasonable speed. In a historical move, the Bruker company decided to harness the skills of the scientific software development community by releasing to the public the timsTOF data file format specification.
View Article and Find Full Text PDFIn , the breaking of seed dormancy in wild type (Col-0) by ethylene at 100 μL L required at least 30 h application. A mutant of the proteolytic N-degron pathway, lacking the E3 ligase (), was investigated for its role in ethylene-triggered changes in proteomes during seed germination. Label-free quantitative proteomics was carried out on dormant wild type Col-0 and seeds treated with (+) or without (-) ethylene.
View Article and Find Full Text PDFSeed germination is critical for early plantlet development and is tightly controlled by environmental factors. Nevertheless, the signaling networks underlying germination control remain elusive. In this study, the remodeling of Arabidopsis seed phosphoproteome during imbibition was investigated using stable isotope dimethyl labeling and nanoLC-MS/MS analysis.
View Article and Find Full Text PDFCalcium signaling mediates most developmental processes and stress responses in plants. Among plant calcium sensors, the calcium-dependent protein kinases display a unique structure harboring both calcium sensing and kinase responding activities. AtCPK5 is an essential member of this family in Arabidopsis that regulates immunity and abiotic stress tolerance.
View Article and Find Full Text PDFPhosphoglycerate mutases (PGAMs) catalyse the reversible isomerisation of 3-phosphoglycerate and 2-phosphoglycerate, a step of glycolysis. PGAMs can be sub-divided into 2,3-bisphosphoglycerate-dependent (dPGAM) and -independent (iPGAM) enzymes. In plants, phosphoglycerate isomerisation is carried out by cytosolic iPGAM.
View Article and Find Full Text PDFPotassium (K) deficiency is a rather common situation that impacts negatively on biomass, photosynthesis and N assimilation, making K fertilization often unavoidable. Effects of K deficiency have been investigated for several decades and recently progress has been made in identifying metabolomics signatures thereby offering potential to monitor the K status of crops in the field. However, effects of low K conditions could also be due to the antagonism with other nutrients like calcium (Ca) and the well-known biomarker of K deficiency, putrescine, could be a response to Ca/K imbalance rather than K deficiency per se.
View Article and Find Full Text PDFLeaf protein synthesis is an essential process at the heart of plant nitrogen (N) homeostasis and turnover that preferentially takes place in the light, that is, when N and CO fixation occur. The carbon allocation to protein synthesis in illuminated leaves generally accounts for ca. 1 % of net photosynthesis.
View Article and Find Full Text PDFSignal transduction (ST) is essential for rapid adaptive responses to changing environmental conditions. It acts through rapid post-translational modifications of signalling proteins and downstream effectors that regulate the activity and/or subcellular localisation of target proteins, or the expression of downstream genes. We have performed a quantitative, comparative proteomics study of ST mutants in the phytopathogenic fungus Botrytis cinerea during axenic growth under non-stressed conditions to decipher the roles of two kinases of the hyper-osmolarity pathway in B.
View Article and Find Full Text PDFAlbumins and globulins (AGs) of wheat endosperm represent about 20% of total grain proteins. Some of these physiologically active proteins can influence the synthesis of storage proteins (SPs) (gliadins and glutenins) and consequently, rheological properties of wheat flour and processing. To identify such AGs, data, (published by Bonnot et al.
View Article and Find Full Text PDFOil palm is by far the major oil-producing crop on the global scale, with c. 62 Mt oil produced each year. This species is a strong potassium (K)-demanding species cultivated in regions where soil K availability is generally low and waterlogging due to tropical heavy rains can limit further nutrient absorption.
View Article and Find Full Text PDFMitochondria play a central role in cellular energy metabolism and cell death. Deregulation of mitochondrial functions is associated with several human pathologies (neurodegenerative diseases, neuromuscular diseases, type II diabetes, obesity, cancer). The steadily increasing number of identified mitochondrial phosphoproteins, kinases, and phosphatases in recent years suggests that reversible protein phosphorylation plays an important part in the control of mitochondrial processes.
View Article and Find Full Text PDFWheat grain storage proteins (GSPs) make up most of the protein content of grain and determine flour end-use value. The synthesis and accumulation of GSPs depend highly on nitrogen (N) and sulfur (S) availability and it is important to understand the underlying control mechanisms. Here we studied how the einkorn (Triticum monococcum ssp.
View Article and Find Full Text PDFConsiderable efforts are currently devoted to understanding the regulation of primary carbon metabolism in plant leaves, which is known to change dramatically with environmental conditions, e.g. during light/dark transitions.
View Article and Find Full Text PDFProtein translation is an energy consuming process that has to be fine-tuned at both the cell and organism levels to match the availability of resources. The target of rapamycin kinase (TOR) is a key regulator of a large range of biological processes in response to environmental cues. In this study, we have investigated the effects of TOR inactivation on the expression and regulation of Arabidopsis ribosomal proteins at different levels of analysis, namely from transcriptomic to phosphoproteomic.
View Article and Find Full Text PDFUnlabelled: Arabidopsis thaliana cytosolic ribosomes are large complexes containing eighty-one distinct ribosomal proteins (r-proteins), four ribosomal RNAs (rRNA) and a plethora of associated (non-ribosomal) proteins. In plants, r-proteins of cytosolic ribosomes are each encoded by two to seven different expressed and similar genes, forming an r-protein family. Distinctions in the r-protein coding sequences of gene family members are a source of variation between ribosomes.
View Article and Find Full Text PDFThe nuclear proteome of the grain of the two cultivated wheat species Triticum aestivum (hexaploid wheat; genomes A, B, and D) and T. monococcum (diploid wheat; genome A) was analyzed in two early stages of development using shotgun-based proteomics. A procedure was optimized to purify nuclei, and an improved protein sample preparation was developed to efficiently remove nonprotein substances (starch and nucleic acids).
View Article and Find Full Text PDFCellulose is one of the most important organic compounds in terrestrial ecosystems and represents a major plant structural polymer. However, knowledge of the regulation of cellulose biosynthesis is still rather limited. Recent studies have shown that the phosphorylation of cellulose synthases (CESAs) may represent a key regulatory event in cellulose production.
View Article and Find Full Text PDFThis study describes the gel-free phosphoproteomic analysis of the phytopathogenic fungi Alternaria brassicicola and Botrytis cinerea grown in vitro under nonlimiting conditions. Using a combination of strong cation exchange and IMAC prior to LC-MS, we identified over 1350 phosphopeptides per fungus representing over 800 phosphoproteins. The preferred phosphorylation sites were found on serine (>80%) and threonine (>15%), whereas phosphorylated tyrosine residues were found at less than 1% in A.
View Article and Find Full Text PDFUnlabelled: The yeast Saccharomyces cerevisiae is a facultative aerobe able to adapt its metabolism according to the carbon substrate. The mechanisms of these adaptations involve at least partly the mitochondria but are not yet well understood. To address the possible role of protein phosphorylation event in their regulation, it is necessary in a first instance to determine precisely the phosphorylation sites that show changes depending on the carbon source.
View Article and Find Full Text PDFBackground: Genetic evidence in Arabidopsis thaliana indicates that members of the Snf1-Related Kinases 2 family (SnRK2) are essential in mediating various stress-adaptive responses. Recent reports have indeed shown that one particular member, Open Stomata (OST)1, whose kinase activity is stimulated by the stress hormone abscisic acid (ABA), is a direct target of negative regulation by the core ABA co-receptor complex composed of PYR/PYL/RCAR and clade A Protein Phosphatase 2C (PP2C) proteins.
Methodology/principal Findings: Here, the substrate preference of OST1 was interrogated at a genome-wide scale.
The plant hormone abscisic acid (ABA) triggers production of reactive oxygen species (ROS) in guard cells via the AtrbohD and AtrbohF NADPH oxidases, leading to stomatal closure. The ABA-activated SnRK2 protein kinase open stomata 1 (OST1) (SRK2E/SnRK2.6) acts upstream of ROS in guard cell ABA signaling.
View Article and Find Full Text PDFBackground: Allopolyploidy is a preeminent process in plant evolution that results from the merger of distinct genomes in a common nucleus via inter-specific hybridization. Allopolyploid formation is usually related to genome-wide structural and functional changes though the underlying mechanisms operating during this "genomic shock" still remain poorly known. The aim of the present study was to investigate the modifications occurring at the proteomic level following an allopolyploidization event and to determine whether these changes are related to functional properties of the proteins.
View Article and Find Full Text PDFThe roles of two cytosolic maize glutamine synthetase isoenzymes (GS1), products of the Gln1-3 and Gln1-4 genes, were investigated by examining the impact of knockout mutations on kernel yield. In the gln1-3 and gln1-4 single mutants and the gln1-3 gln1-4 double mutant, GS mRNA expression was impaired, resulting in reduced GS1 protein and activity. The gln1-4 phenotype displayed reduced kernel size and gln1-3 reduced kernel number, with both phenotypes displayed in gln1-3 gln1-4.
View Article and Find Full Text PDFA lack of competence to form adventitious roots by cuttings or explants in vitro occurs routinely and is an obstacle for the clonal propagation and rapid fixation of elite genotypes. Adventitious rooting is known to be a quantitative genetic trait. We performed a proteomic analysis of Arabidopsis (Arabidopsis thaliana) mutants affected in their ability to develop adventitious roots in order to identify associated molecular markers that could be used to select genotypes for their rooting ability and/or to get further insight into the molecular mechanisms controlling adventitious rooting.
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