Levels of furan in foods from the first French Total Diet Study on infants and toddlers.

This study describes an optimisation and validation process on a method using gas chromatography coupled with mass spectrometry to quantify furan in foods consumed mainly by infants and toddlers. The method that we developed allowed for low limits of quantification for liquid (1 µg kg) and solid (2 µg kg) samples. Our method was then applied to 134 food samples from the first French Total Diet Study on infants and toddlers.

Ochratoxin A determination in swine muscle and liver from French conventional or organic farming production systems.

Consumers generally considered organic products to be healthier and safer but data regarding the contamination of organic products are scarce. This study evaluated the impact of the farming system on the levels of ochratoxin A (OTA) in the tissues of French pigs (muscle and liver) reared following three different types of production (organic, Label Rouge and conventional). Because OTA is present at trace levels in animal products, a sensitive ultra-high performance liquid chromatography-tandem mass spectrometry method using stable isotope dilution assay was developed and validated.

NDPK-D (NM23-H4)-mediated externalization of cardiolipin enables elimination of depolarized mitochondria by mitophagy.

Mitophagy is critical for cell homeostasis. Externalization of the inner mitochondrial membrane phospholipid, cardiolipin (CL), to the surface of the outer mitochondrial membrane (OMM) was identified as a mitophageal signal recognized by the microtubule-associated protein 1 light chain 3. However, the CL-translocating machinery remains unknown.

Membrane trafficking. Nucleoside diphosphate kinases fuel dynamin superfamily proteins with GTP for membrane remodeling.

Dynamin superfamily molecular motors use guanosine triphosphate (GTP) as a source of energy for membrane-remodeling events. We found that knockdown of nucleoside diphosphate kinases (NDPKs) NM23-H1/H2, which produce GTP through adenosine triphosphate (ATP)-driven conversion of guanosine diphosphate (GDP), inhibited dynamin-mediated endocytosis. NM23-H1/H2 localized at clathrin-coated pits and interacted with the proline-rich domain of dynamin.

Metal sensing and signal transduction by CnrX from Cupriavidus metallidurans CH34: role of the only methionine assessed by a functional, spectroscopic, and theoretical study.

When CnrX, the periplasmic sensor protein in the CnrYXH transmembrane signal transduction complex of Cupriavidus metallidurans CH34, binds the cognate metal ions Ni(II) or Co(II), the ECF-type sigma factor CnrH is made available in the cytoplasm for the RNA-polymerase to initiate transcription at the cnrYp and cnrCp promoters. Ni(II) or Co(II) are sensed by a metal-binding site with a N3O2S coordination sphere with octahedral geometry, where S stands for the thioether sulfur of the only methionine (Met123) residue of CnrX. The M123A-CnrX derivative has dramatically reduced signal propagation in response to metal sensing while the X-ray structure of Ni-bound M123A-CnrXs showed that the metal-binding site was not affected by the mutation.