The Escherichia coli envelope stress sensor CpxA can sense changes in lipid bilayer properties

The Cpx stress response system is induced by various environmental and cellular stimuli. It is also activated in Escherichia coli strains lacking the major phospholipid, phosphatidylethanolamine (PE). However, it is not known whether CpxA directly senses changes in the lipid bilayer or the presence of misfolded proteins due to the lack of PE in their membranes. To address this question, we used an in vitro reconstitution system and vesicles with different lipid compositions to track modulations in the activity of CpxA in different lipid bilayers. Moreover, the Cpx response was validated in vivo by monitoring expression of a PcpxP-gfp reporter in lipid-engineered strains of E. coli. Our combined data indicate that CpxA responds specifically to different lipid compositions

Intercomparison exercise in analysis of DTM in decommissioning waste

An intercomparison exercise was carried out for difficult to measure radionuclides in activated reactor pressure vessel steel samples. The results were analysed according to ISO 13528 standard. The performance assessment was carried out using z score. Report includes an overview of the radioanalytical procedures, preliminary and final results, and performance assessments