Targeting N-myristoylation for therapy of B-cell lymphomas

N-myristoyltransferases (NMTs) target many signaling proteins to membranes. Here the authors show an NMT inhibitor named PCLX-001 selectively kills lymphoma cells by shutting down their main survival signaling pathway and offers an additional treatment strategy for lymphoma patients

Is the meiofauna a good indicator for climate change and anthropogenic impacts?

Our planet is changing, and one of the most pressing challenges facing the scientific community revolves around understanding how ecological communities respond to global changes. From coastal to deep-sea ecosystems, ecologists are exploring new areas of research to find model organisms that help predict the future of life on our planet. Among the different categories of organisms, meiofauna offer several advantages for the study of marine benthic ecosystems. This paper reviews the advances in the study of meiofauna with regard to climate change and anthropogenic impacts. Four taxonomic groups are valuable for predicting global changes: foraminifers (especially calcareous forms), nematodes, copepods and ostracods. Environmental variables are fundamental in the interpretation of meiofaunal patterns and multistressor experiments are more informative than single stressor ones, revealing complex ecological and biological interactions. Global change has a general negative effect on meiofauna, with important consequences on benthic food webs. However, some meiofaunal species can be favoured by the extreme conditions induced by global change, as they can exhibit remarkable physiological adaptations. This review highlights the need to incorporate studies on taxonomy, genetics and function of meiofaunal taxa into global change impact research

A finer look into the twilight zone : comparing acoustic records from an animal-borne miniature sonar and a multifrequency echosounder [résumé]

ICES. Working Group of Fisheries Acoustics, Science and Technology (WGFAST), Somone, SEN, 25-/04/2022 - 28/04/2022An animal-borne miniature active echo-sounder has been recently deployed on southern ele-phant seals (Mirounga leonina) from the Kerguelen and Argentinian colonies. This high frequency sonar (1.5 MHz) has shown a strong potential in detecting small mid-trophic level targets (zoo-plankton and micronekton). Relative abundance and distribution can be assessed, allowing to observe temporal (diel migration) and spatial patterns of plankton. However, the interpretation of the collected data remains uncertain. To address this lack of information, we conducted in situ experiments onboard the Marion Dufresne vessel in the Southern Ocean (10th February to 6th March 2022). The microsonar was fixed on the rosette sampler at 13 locations and attached 16 times to a trawling net (4 mm mesh). Records will be analyzed applying a recent method devel-oped on elephant seals data to detect targets in the beam and estimate organisms abundance. The result will be compared with biological samples and backscattering layers detected by a multifrequency EK80 echosounder (18, 38, 70, 120 and 200 kHz), offering an acoustic landscape of the seals foraging area. This study will benefit to ongoing research regarding biological fields visited by the elephant seals, bringing precision on microsonar target detection capacities

A finer look into the twilight zone : comparing acoustic records from an animal-borne miniature sonar and a multifrequency echosounder [résumé]

ICES. Working Group of Fisheries Acoustics, Science and Technology (WGFAST), Somone, SEN, 25-/04/2022 - 28/04/2022An animal-borne miniature active echo-sounder has been recently deployed on southern ele-phant seals (Mirounga leonina) from the Kerguelen and Argentinian colonies. This high frequency sonar (1.5 MHz) has shown a strong potential in detecting small mid-trophic level targets (zoo-plankton and micronekton). Relative abundance and distribution can be assessed, allowing to observe temporal (diel migration) and spatial patterns of plankton. However, the interpretation of the collected data remains uncertain. To address this lack of information, we conducted in situ experiments onboard the Marion Dufresne vessel in the Southern Ocean (10th February to 6th March 2022). The microsonar was fixed on the rosette sampler at 13 locations and attached 16 times to a trawling net (4 mm mesh). Records will be analyzed applying a recent method devel-oped on elephant seals data to detect targets in the beam and estimate organisms abundance. The result will be compared with biological samples and backscattering layers detected by a multifrequency EK80 echosounder (18, 38, 70, 120 and 200 kHz), offering an acoustic landscape of the seals foraging area. This study will benefit to ongoing research regarding biological fields visited by the elephant seals, bringing precision on microsonar target detection capacities

Mechanisms of metal-phosphates formation in the rhizosphere soils of pea and tomato: environmental and sanitary consequences

International audiencePurpose At the global scale, soil contamination with persistent metals such as lead (Pb), zinc (Zn), and copper (Cu) induces a serious threat of entering the human food chain. In the recent past, different natural and synthetic compounds have been used to immobilizemetals in soil environments. However, the mechanisms involved in amendment-induced immobilization of metals in soil remained unclear. The objective of the present work was therefore to determine the mechanisms involved in metal-phosphates formation in the rhizospheric soils of pea and tomato currently cultivated in kitchen gardens. Materials and methods Pea and tomato were cultivated on a soil polluted by past industrial activities with Pb and Zn under two kinds of phosphate (P) amendments: (1) solid hydroxyapatite and (2) KH2PO4. The nature and quantities of metal-P formed in the rhizospheric soils were studied by using the selective chemical extractions and employing the combination of X-ray fluorescence micro-spectroscopy, scanning electron microscopy, and electron microprobe methods. Moreover, the influence of soil pH and organic acids excreted by plant roots on metal-P complexes formation was studied. Results and discussion Our results demonstrated that P amendments have no effect on metal-P complex formation in the absence of plants. But, in the presence of plants, P amendments cause Pb and Zn immobilization by forming metal-P complexes. Higher amounts of metal-P were formed in the pea rhizosphere compared to the tomato rhizosphere and in the case of soluble P compared to the solid amendment. The increase in soil-metal contact time enhanced metal-P formation. Conclusions The different forms of metal-P formed for the different plants under two kinds of P amendments indicate that several mechanisms are involved in metal immobilization. Metal-P complex formation in the contaminated soil depends on the type of P amendment added, duration of soil-plant contact, type of plant species, and excretion of organic acids by the plant roots in the rhizosphere

Structural and genomic decoding of human and plant myristoylomes reveals a definitive recognition pattern

International audienceAn organism’s entire protein modification repertoire has yet to be comprehensively mapped. N-myristoylation (MYR) is a crucial eukaryotic N-terminal protein modification. Here we mapped complete Homo sapiens and Arabidopsis thaliana myristoylomes. The crystal structures of human modifier NMT1 complexed with reactive and nonreactive target-mimicking peptide ligands revealed unexpected binding clefts and a modifier recognition pattern. This information allowed integrated mapping of myristoylomes using peptide macroarrays, dedicated prediction algorithms, and in vivo mass spectrometry. Global MYR profiling at the genomic scale identified over a thousand novel, heterogeneous targets in both organisms. Surprisingly, MYR involved a non-negligible set of overlapping targets with N-acetylation, and the sequence signature marks for a third proximal acylation—S-palmitoylation—were genomically imprinted, allowing recognition of sequences exhibiting both acylations. Together, the data extend the N-end rule concept for Gly-starting proteins to subcellular compartmentalization and reveal the main neighbors influencing protein modification profiles and consequent cell fate

Similar Intracellular Peptide Profile of TAP1/β2 Microglobulin Double-Knockout Mice and C57BL/6 Wild-Type Mice as Revealed by Peptidomic Analysis

Cells produce and use peptides in distinctive ways. In the present report, using isotope labeling plus semi-quantitative mass spectrometry, we evaluated the intracellular peptide profile of TAP1/β2m−/− (transporter associated with antigen-processing 1/ß2 microglobulin) double-knockout mice and compared it with that of C57BL/6 wild-type animals. Overall, 92 distinctive peptides were identified, and most were shown to have a similar concentration in both mouse strains. However, some peptides showed a modest increase or decrease (~2-fold), whereas a glycine-rich peptide derived from the C-terminal of neurogranin (KGPGPGGPGGAGGARGGAGGGPSGD) showed a substantial increase (6-fold) in TAP1/β2m−/− mice. Thus, TAP1 and β2microglobulin have a small influence on the peptide profile of neuronal tissue, suggesting that the presence of peptides derived from intracellular proteins in neuronal tissue is not associated with antigens of the class I major histocompatibility complex. Therefore, it is possible that these intracellular peptides play a physiological role