Perturbation par les ions lithium de caracteristiques ioniques des suspensions cellulaires d'Acer pseudoplatanus L

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Effects of iron limitation on growth and carbon metabolism in oceanic and coastal heterotrophic bacteria

International audienc

Enhanced adhesion of Campylobacter jejuni to abiotic surfaces is mediated by membrane proteins in oxygen-enriched conditions

Campylobacter jejuni is responsible for the major foodborne bacterial enteritis in humans. In contradiction with its fastidious growth requirements, this microaerobic pathogen can survive in aerobic food environments, suggesting that it must employ a variety of protection mechanisms to resist oxidative stress. For the first time, C. jejuni 81-176 inner and outer membrane subproteomes were analyzed separately using two-dimensional protein electrophoresis (2-DE) of oxygen-acclimated cells and microaerobically grown cells. LC-MS/MS analyses successfully identified 42 and 25 spots which exhibited a significantly altered abundance in the IMP-enriched fraction and in the OMP-enriched fraction, respectively, in response to oxidative conditions. These spots corresponded to 38 membrane proteins that could be grouped into different functional classes: (i) transporters, (ii) chaperones, (iii) fatty acid metabolism, (iv) adhesion/virulence and (v) other metabolisms. Some of these proteins were up-regulated at the transcriptional level in oxygen-acclimated cells as confirmed by qRT-PCR. Downstream analyses revealed that adhesion of C. jejuni to inert surfaces and swarming motility were enhanced in oxygen-acclimated cells or paraquat-stressed cells, which could be explained by the higher abundance of membrane proteins involved in adhesion and biofilm formation. The virulence factor CadF, over-expressed in the outer membrane of oxygen-acclimated cells, contributes to the complex process of C. jejuni adhesion to inert surfaces as revealed by a reduction in the capability of C. jejuni 81-176 DCadF cells compared to the isogenic strain. Taken together, these data demonstrate that oxygen-enriched conditions promote the over-expression of membrane proteins involved in both the biofilm initiation and virulence of C. jejuni

Analysis of LuPME3, a pectin methylesterase from Linum usitatissimum, revealed a variability in PME proteolytic maturation

Pectin methylesterase (PME) catalyzes the de-methylesterification of pectin in plant cell walls during cell elongation.1 Pectins are mainly composed of α(1, 4)-D-galacturonosyl acid units that are synthesized in a methylesterified form in the Golgi apparatus to prevent any interaction with Ca2+ ions during their intracellular transport.2 The highly methylesterified pectins are then secreted into the apoplasm3 and subsequently de-methylesterified in muro by PMEs. This can either induce the formation of pectin gels through the Ca2+ crosslinking of neighboring non-methylesterified chains or create substrates for pectin-degrading enzymes such as polygalacturonases and pectate lyases for the initiation of cell wall loosening.4 PMEs belong to a large multigene family. Sixty­six PME-related genes are predicted in the Arabidopsis genome.1 Among them, we have recently shown that AtPME3 (At3g14310), a major basic PME isoform in A. thaliana, is ubiquitously expressed in vascular tissues and play a role in adventitious rooting.5 In flax (Linum usitatissimum), three genes encoding PMEs have been sequenced so far, including LuPME3, the ortholog of AtPME3. Analysis of the LuPME3 isoform brings new insights into the processing of these proteins

Determination of the collision cross sections of cardiolipins and phospholipids from Pseudomonas aeruginosa by traveling wave ion mobility spectrometry-mass spectrometry using a novel correction strategy

International audienc

Membrane phospholipid composition of Pseudomonas aeruginosa grown in a cystic fibrosis mucus-mimicking medium

International audienc

Antibacterial Activity of Ciprofloxacin‐Loaded Poly(lactic‐co‐glycolic acid)‐Nanoparticles Against Staphylococcus aureus

International audienc

Glioprotective effect of Ulva rigida extract against UVB cellular damages

International audienc

Kiwi fruit PMEI inhibits PME activity, modulates root elongation and induces pollen tube burst in Arabidopsis thaliana

International audienc