MADS transcription factors cooperate: complexities of complex formation.

This article comments on: A conserved leucine zipper-like motif accounts for strong tetramerization capabilities of SEPALLATA-like MADS-domain transcription factors. Journal of Experimental Botany 1943–1954.

Grazer-induced transcriptomic and metabolomic response of the chain-forming diatom Skeletonema marinoi.

Diatoms and copepods are main actors in marine food webs. The prey-predator interactions between them affect bloom dynamics, shape marine ecosystems and impact the energy transfer to higher trophic levels. Recently it has been demonstrated that the presence of grazers may affect the diatom prey beyond the direct effect of grazing.

Tetramerization of MADS family transcription factors SEPALLATA3 and AGAMOUS is required for floral meristem determinacy in Arabidopsis.

The MADS transcription factors (TF) constitute an ancient family of TF found in all eukaryotes that bind DNA as obligate dimers. Plants have dramatically expanded the functional diversity of the MADS family during evolution by adding protein-protein interaction domains to the core DNA-binding domain, allowing the formation of heterotetrameric complexes. Tetramerization of plant MADS TFs is believed to play a central role in the evolution of higher plants by acting as one of the main determinants of flower formation and floral organ specification.

Sequencing, Assembly, and Annotation of the Complete Genome of a New Thraustochytrid Species, Strain CCAP_4062/3.

Thraustochytrids are ecologically and biotechnologically relevant marine species. We report here the assembly and annotation of the whole-genome sequence of a new thraustochytrid strain, CCAP_4062/3. The genome size was estimated at 38.

Screening for Biologically Annotated Drugs That Trigger Triacylglycerol Accumulation in the Diatom .

Microalgae are a promising feedstock for the production of triacylglycerol (TAG) for a variety of potential applications, ranging from food and human health to biofuels and green chemistry. However, obtaining high TAG yields is challenging. A phenotypic assay for the accumulation of oil droplets was developed to screen a library of 1,200 drugs, annotated with pharmacology information, to select compounds that trigger TAG accumulation in the diatom Using this screen, we identified 34 molecules acting in a dose-dependent manner.

The ethical concerns about transgenic crops.

It is generally accepted that transgenesis can improve our knowledge of natural processes, but also leads to agricultural, industrial or socio-economical changes which could affect human society at large and which may, consequently, require regulation. It is often stated that developing countries are most likely to benefit from plant biotechnology and are at the same time most likely to be affected by the deployment of such new technologies. Therefore, ethical questions related to such biotechnology probably also need to be addressed.

Auxin Response Factors (ARFs) are potential mediators of auxin action in tomato response to biotic and abiotic stress (Solanum lycopersicum).

Survival biomass production and crop yield are heavily constrained by a wide range of environmental stresses. Several phytohormones among which abscisic acid (ABA), ethylene and salicylic acid (SA) are known to mediate plant responses to these stresses. By contrast, the role of the plant hormone auxin in stress responses remains so far poorly studied.

Intramolecular crosstalk between catalytic activities of receptor kinases.

Signal modulation is important for the growth and development of plants and this process is mediated by a number of factors including physiological growth regulators and their associated signal transduction pathways. Protein kinases play a central role in signaling, including those involving pathogen response mechanisms. We previously demonstrated an active guanylate cyclase (GC) catalytic center in the brassinosteroid insensitive receptor (AtBRI1) within an active intracellular kinase domain resulting in dual enzymatic activity.

Thermoacclimation and genome adaptation of the membrane lipidome in marine Synechococcus.

The marine cyanobacteria of the genus Synechococcus are important primary producers, displaying a wide latitudinal distribution that is underpinned by diversification into temperature ecotypes. The physiological basis underlying these ecotypes is poorly known. In many organisms, regulation of membrane fluidity is crucial for acclimating to variations in temperature.

Exploring the Multiligand Binding Specificity of Saposin B Reveals Two Binding Sites.

Saposin B (SapB) is a human lysosomal protein, critical for the degradation of -sulfogalactosylceramide (sulfatide). SapB binds sulfatide and presents it to the active site of the enzyme arylsulfatase A. Deficiency of SapB leads to fatal activator-deficient metachromatic leukodystrophy.

Preparation of Membrane Fractions (Envelope, Thylakoids, Grana, and Stroma Lamellae) from Arabidopsis Chloroplasts for Quantitative Proteomic Investigations and Other Studies.

Chloroplasts are semiautonomous organelles found in plants and protists. They are surrounded by a double membrane system, or envelope. These envelope membranes contain machineries to import nuclear-encoded proteins, and transporters for ions or metabolites, but are also essential for a range of plastid-specific metabolisms.

Mechanisms of Phosphorus Acquisition and Lipid Class Remodeling under P Limitation in a Marine Microalga.

Molecular mechanisms of phosphorus (P) limitation are of great interest for understanding algal production in aquatic ecosystems. Previous studies point to P limitation-induced changes in lipid composition. As, in microalgae, the molecular mechanisms of this specific P stress adaptation remain unresolved, we reveal a detailed phospholipid-recycling scheme in and describe important P acquisition genes based on highly corresponding transcriptome and lipidome data.

Inhibition of Phytophthora species, agents of cocoa black pod disease, by secondary metabolites of Trichoderma species.

Cocoa production is affected by the black pod disease caused by several Phytophthora species that bring, about each year, an estimated loss of 44% of world production. Chemical control remains expensive and poses an enormous risk of poisoning for the users and the environment. Biocontrol by using antagonistic microorganisms has become an alternative to the integrated control strategy against this disease.

Adaptive Actin Networks.

Despite their fundamental importance in the regulation of cell physiology, the mechanisms that confer cell adaptability to changes in the microenvironment are poorly understood. A recent study in Cell (Mueller et al., 2017) examines the capability of branched actin networks to respond and adapt to mechanical load in vivo.

Dihydrofolate Reductase/Thymidylate Synthase Fine-Tunes the Folate Status and Controls Redox Homeostasis in Plants.

Folates (B9 vitamins) are essential cofactors in one-carbon metabolism. Since C1 transfer reactions are involved in synthesis of nucleic acids, proteins, lipids, and other biomolecules, as well as in epigenetic control, folates are vital for all living organisms. This work presents a complete study of a plant (dihydrofolate reductase-thymidylate synthase) gene family that implements the penultimate step in folate biosynthesis.

Network heterogeneity regulates steering in actin-based motility.

The growth of branched actin networks powers cell-edge protrusions and motility. A heterogeneous density of actin, which yields to a tunable cellular response, characterizes these dynamic structures. We study how actin organization controls both the rate and the steering during lamellipodium growth.

Nitric Oxide Mediates Nitrite-Sensing and Acclimation and Triggers a Remodeling of Lipids.

Nitric oxide (NO) is an intermediate of the nitrogen cycle, an industrial pollutant, and a marker of climate change. NO also acts as a gaseous transmitter in a variety of biological processes. The impact of environmental NO needs to be addressed.

Adaptive Response of Actin Bundles under Mechanical Stress.

Actin is one of the main components of the architecture of cells. Actin filaments form different polymer networks with versatile mechanical properties that depend on their spatial organization and the presence of cross-linkers. Here, we investigate the mechanical properties of actin bundles in the absence of cross-linkers.

Stem Cell-Like Properties of CK2β-down Regulated Mammary Cells.

The ubiquitous protein kinase CK2 has been demonstrated to be overexpressed in a number of human tumours. This enzyme is composed of two catalytic α or α' subunits and a dimer of β regulatory subunits whose expression levels are probably implicated in CK2 regulation. Several recent papers reported that unbalanced expression of CK2 subunits is sufficient to drive epithelial to mesenchymal transition, a process involved in cancer invasion and metastasis.

A systems-wide understanding of photosynthetic acclimation in algae and higher plants.

The ability of phototrophs to colonise different environments relies on robust protection against oxidative stress, a critical requirement for the successful evolutionary transition from water to land. Photosynthetic organisms have developed numerous strategies to adapt their photosynthetic apparatus to changing light conditions in order to optimise their photosynthetic yield, which is crucial for life on Earth to exist. Photosynthetic acclimation is an excellent example of the complexity of biological systems, where highly diverse processes, ranging from electron excitation over protein protonation to enzymatic processes coupling ion gradients with biosynthetic activity, interact on drastically different timescales from picoseconds to hours.

A Microsomal Proteomics View of H₂O₂- and ABA-Dependent Responses.

The plant hormone abscisic acid (ABA) modulates a number of plant developmental processes and responses to stress. In planta, ABA has been shown to induce reactive oxygen species (ROS) production through the action of plasma membrane-associated nicotinamide adenine dinucleotide phosphate (NADPH)-oxidases. Although quantitative proteomics studies have been performed to identify ABA- or hydrogen peroxide (H₂O₂)-dependent proteins, little is known about the ABA- and H₂O₂-dependent microsomal proteome changes.

LC-MS/MS versus TLC plus GC methods: Consistency of glycerolipid and fatty acid profiles in microalgae and higher plant cells and effect of a nitrogen starvation.

Methods to analyze lipidomes have considerably evolved, more and more based on mass spectrometry technics (LC-MS/MS). However, accurate quantifications using these methods require 13C-labeled standards for each lipid, which is not feasible because of the very large number of molecules. Thus, quantifications rely on standard molecules representative of a whole class of lipids, which might lead to false estimations of some molecular species.

Investigating mixotrophic metabolism in the model diatom .

Diatoms are prominent marine microalgae, interesting not only from an ecological point of view, but also for their possible use in biotechnology applications. They can be cultivated in phototrophic conditions, using sunlight as the sole energy source. Some diatoms, however, can also grow in a mixotrophic mode, wherein both light and external reduced carbon contribute to biomass accumulation.

Structure of the TOPLESS corepressor provides insight into the evolution of transcriptional repression.

Transcriptional repression involves a class of proteins called corepressors that link transcription factors to chromatin remodeling complexes. In plants such as , the most prominent corepressor is TOPLESS (TPL), which plays a key role in hormone signaling and development. Here we present the crystallographic structure of the TPL N-terminal region comprising the LisH and CTLH (C-terminal to LisH) domains and a newly identified third region, which corresponds to a CRA domain.

Evolution of DMSP (dimethylsulfoniopropionate) biosynthesis pathway: Origin and phylogenetic distribution in polyploid Spartina (Poaceae, Chloridoideae).

DMSP (dimethylsulfoniopropionate) is an ecologically important sulfur metabolite commonly produced by marine algae and by some higher plant lineages, including the polyploid salt marsh genus Spartina (Poaceae). The molecular mechanisms and genes involved in the DMSP biosynthesis pathways are still unknown. In this study, we performed comparative analyses of DMSP amounts and molecular phylogenetic analyses to decipher the origin of DMSP in Spartina that represents one of the major source of terrestrial DMSP in coastal marshes.