A5063908583- Lipid metabolism and biosynthesis
- Protist diversity and phylogeny
- Microbial Metabolic Engineering and Bioproduction
- Photosynthetic Processes and Mechanisms
- Microbial Community Ecology and Physiology
- Cellular transport and secretion
- Plant biochemistry and biosynthesis
- Edible Oils Quality and Analysis
- Food Chemistry and Fat Analysis
- Fungal and yeast genetics research
- Plant Reproductive Biology
- Spectroscopy Techniques in Biomedical and Chemical Research
- Microtubule and mitosis dynamics
- Proteins in Food Systems
- Fermentation and Sensory Analysis
- Agriculture and Rural Development Research
- Endoplasmic Reticulum Stress and Disease
- Photoreceptor and optogenetics research
- Genomics and Phylogenetic Studies
- Nuts composition and effects
- Ubiquitin and proteasome pathways
- Lipid Membrane Structure and Behavior
- Glycosylation and Glycoproteins Research
- Metabolomics and Mass Spectrometry Studies
- Microbial Natural Products and Biosynthesis
Institut Jean-Pierre Bourgin
2014-2025
Université Paris-Saclay
2012-2025
AgroParisTech
2007-2025
Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
2023-2025
Centre National de la Recherche Scientifique
2001-2015
Institut National de la Recherche Agronomique
2013-2015
Sorbonne Université
2004-2008
Biopolymères Interactions Assemblages
2007
Centre de Génétique Moléculaire
2000-2006
Institut Jacques Monod
2003-2006
In oleaginous seeds, lipids—stored in organelles called oil bodies (OBs)—are degraded post-germinatively to provide carbon and energy for seedling growth. To date, little is known about how OB coat proteins, as oleosins, control dynamics during seed germination. Here, we demonstrated that the sequential proteolysis of five Arabidopsis thaliana oleosins OLE1–OLE5 begins just prior lipid degradation. Several post-translational modifications (e.g. phosphorylation ubiquination) were concomitant...
Exploring and deciphering the biodiversity of oil bodies (OBs) recovered from oilseeds are growing interest in preparation sustainable, natural healthy plant-based food products. This study focused on chia (Salvia hispanica L.) camelina (Camelina sativa seed OBs. A green refinery process including ultrasound to remove mucilage, aqueous extraction by grinding centrifugation recover OBs seeds was used. The microstructure, composition physical stability were examined. Confocal laser scanning...
Proteomic approaches on lipid bodies have led to the identification of proteins associated with this compartment, showing that, rather than inert fat depot, droplets appear as complex dynamic organelles roles in metabolism control and cell signaling. We focused our investigations caleosin [Arabidopsis thaliana 1 (AtClo1)], a minor protein Arabidopsis seed body. AtClo1 shares an original triblock structure, which confers capacity insert at body surface. In addition, possesses calcium-binding...
Precursor forms of vacuolar proteins with transmembrane domains, such as the carboxypeptidase S Cps1p and polyphosphatase Phm5p, are selectively sorted in endosomal compartments to vesicles that invaginate, budding into lumen late endosomes, resulting formation multivesicular bodies (MVBs). These then delivered following fusion MVBs vacuole. The sorting Phm5p these structures is mediated by ubiquitylation, doa4 mutant cells, which have reduced level free ubiquitin, missorted membrane. A...
Eukaryotic plasma membrane transporters are subjected to a tightly regulated intracellular trafficking. The yeast siderophore iron transporter1 (Sit1) displays substrate-regulated It is targeted the or vacuolar degradative pathway when synthesized in presence absence of external substrate, respectively. Sorting Sit1 dependent on clathrin adaptor Gga2, and more specifically its C-GAT subdomain. Plasma undergoes substrate-induced ubiquitylation Rsp5 ubiquitin protein ligase. also ubiquitylated...
It has now been clearly shown that lipid droplets (LDs) play a dynamic role in the cell. This was reinforced by LD proteomics which suggest significant number of trafficking proteins are associated with this organelle. Using microscopy, we showed LDs partly co-localize vacuole S. cerevisiae. Immunoblot experiments confirmed association vacuolar Rab GTPase Rab7-like Ypt7p LDs. We observed an increase fatty acid content and ypt7Δ mutant also changes morphology intra fusions, revealing direct...
Streptomyces lividans TK24 is a strain that naturally produces antibiotics at low levels, but dramatic overproduction of occurs upon interruption the ppk gene. However, role Ppk enzyme in relation to regulation antibiotic biosynthesis remains poorly understood. In order gain better understanding phenotype mutant, proteomes wild-type (wt) and mutant strains, grown for 96 h on R2YE medium limited phosphate, were analyzed. Intracellular proteins separated two-dimensional (2D) gels, spots...
The vacuolar proton-ATPase (V-ATPase) is a multisubunit enzyme complex that able to transfer protons over membranes against an electrochemical potential under ATP hydrolysis. consists of two subcomplexes: V0, which membrane embedded; and V1, cytosolic. V0 was also reported be involved in fusion vacuoles yeast. We identified six genes encoding c-subunits (proteolipids) F-subunits V1 studied the role V-ATPase trafficking Paramecium. Green fluorescent protein (GFP) proteins allowed clear...
In Saccharomyces cerevisiae, deficiencies in the ESCRT machinery trigger mistargeting of endocytic and biosynthetic ubiquitinated cargoes to limiting membrane vacuole. Surprisingly, impairment this also leads accumulation various receptors transporters at plasma both yeast higher eukaryotes. Using well-characterized cargo uracil permease (Fur4p), we show here that apparent stabilization mutants results from an efficient recycling protein. Whereas several proteins as well internalized dyes...
Summary In order to establish the biological function of tobacco basic leucine zipper (bZIP) transcription factor BZI-1 in hormone signalling, we have analysed transgenic plants which were altered with respect protein level or activation potential BZI-1. Overexpression a dominant-negative derivative BZI-1, lacking N-terminal domain, resulted displaying reduced internode size, enhanced lateral shoot formation and small, curly leaves. The response auxin monitored reference root organogenesis,...
Oleosins are hydrophobic proteins from oleaginous seeds, surrounding and stabilizing oil bodies. They known to display interesting interfacial properties. Specific sera were raised against four different A. thaliana oleosins used in dot-blot assays for oleosin quantification. These set up extraction of seeds. One mixture chloroform/methanol gave optimal extraction. Extracted represented 9% seed identified by immunoblot proteomic analyses. accounted 79% the extracted proteins. This simple...
We have studied the intracellular trafficking of Sit1 [ferrioxamine B (FOB) transporter] and Enb1 (enterobactin transporter) in Saccharomyces cerevisiae using green fluorescent protein (GFP) fusion proteins. was constitutively targeted to plasma membrane. essentially vacuolar degradation pathway when synthesized absence substrate. Massive membrane sorting induced by various siderophore substrates Sit1, coprogen, which is not a substrate Sit1. Thus, different transporters use regulated...
In most organisms, storage lipids are packaged into specialized structures called lipid droplets. These contain a core of neutral surrounded by monolayer phospholipids, and various proteins which vary depending on the species. Hydrophobic structural stabilize interface between aqueous cellular environment (perilipin family proteins, apolipoproteins, oleosins). We developed genetic approach using heterologous expression in Saccharomyces cerevisiae Arabidopsis thaliana droplet oleosin caleosin...
ABSTRACT We report a random survey of 1 to 2% the somatic genome free-living ciliate Paramecium tetraurelia by single-run sequencing ends plasmid inserts. As in all ciliates, germ line (100 200 Mb) is reproducibly rearranged at each sexual cycle produce expressed or potentially genes, stripped repeated sequences, transposons, and AT-rich unique sequence elements limited line. found be compact (>68% coding, estimated from several complete library inserts) feature uniformly small introns...
N-ethylmaleimide (NEM)-sensitive factor (NSF), a regulator of soluble NSF attachment protein receptors (SNAREs), is required for vesicular transport in many eukaryotic cells. In the ciliated protozoon Paramecium, complex but well-defined routes exist, constitutive and regulated exocytosis, endocytosis, phagocytosis fluid excretory pathway through contractile vacuoles, that can all be studied independently at whole cell level. To unravel role SNARE machinery this traffic, we looked genes...
Oil from oleaginous seeds is mainly composed of triacylglycerols. Very long chain fatty acids (VLCFAs) are major constituents triacylglycerols in many seed oils and represent valuable feedstock for industrial purposes. To identify genetic factors governing natural variability VLCFA biosynthesis, a quantitative trait loci (QTL) analysis using recombinant inbred line population derived cross between accessions Bay-0 Shahdara was performed Arabidopsis thaliana. Two acid length ratio (CLR) QTL...
Abstract In Paramecium, a number of mutants affected in the exocytotic membrane fusion step regulated secretory pathway have been obtained. Here, we report isolation one corresponding genes, ND9, previously suspected to encode soluble protein interacting with both plasma and trichocyst membranes. Nd9p is novel polypeptide that contains C-terminal Armadillo-like repeats. Point mutations were found first N-terminal quarter molecule last putative Armadillo repeat, respectively, for two...
Abstract In exocytosis, secretory granules contact plasma membrane at sites where microdomains can be observed, which are sometimes marked by intramembranous particle arrays. Such arrays particularly obvious when fusion is frozen a subterminal stage, e.g., in neuromuscular junctions and ciliate exocytotic sites. Paramecium, genetic approach has shown that the “rosettes” of particles essential for stimulated exocytosis granules, trichocysts. The identification two genes encoding...
Plasma membrane proteins involved in transport processes play a crucial role cell physiology. On account of these properties, molecules are ideal targets for development new therapeutic and agronomic agents. However, low abundance, which limits their study. Although yeast seems expressing heterologous transporters, plasma often retained intracellular compartments. We tried to find mutants potentially able improve functional expression whole set transporters. focused on Arabidopsis thaliana...
Yeasts belonging to the subphylum Saccharomycotina have been used for centuries in food processing and, more recently, biotechnology. Over past few decades, these yeasts also studied interest of their potential produce oil replace fossil resources. Developing massive production requires increasing yield and modifying profiles fatty acids contained satisfy specific technical requirements. For example, derivatives medium-chain (MCFAs, containing 6-14 carbons) are biodiesels, cleaning products,...