Tribological properties of room temperature fluorinated graphite heat-treated under fluorine atmosphere

This work is concerned with the study of the tribologic properties of room temperature fluorinated graphite heat-treated under fluorine atmosphere. The fluorinated compounds all present good intrinsic friction properties (friction coefficient in the range 0.05–0.09). The tribologic performances are optimized if the materials present remaining graphitic domains (influenced by the presence of intercalated fluorinated species) whereas the perfluorinated compounds, where the fluorocarbon layers are corrugated (armchair configuration of the saturated carbon rings) present higher friction coefficients. Raman analyses reveal that the friction process induces severe changes in the materials structure especially the partial re-building of graphitic domains in the case of perfluorinated compounds which explains the improvement of μ during the friction tests for these last materials

Reversible inhibitor of p97, DBeQ, impairs both ubiquitin-dependent and autophagic protein clearance pathways

A specific small-molecule inhibitor of p97 would provide an important tool to investigate diverse functions of this essential ATPase associated with diverse cellular activities (AAA) ATPase and to evaluate its potential to be a therapeutic target in human disease. We carried out a high-throughput screen to identify inhibitors of p97 ATPase activity. Dual-reporter cell lines that simultaneously express p97-dependent and p97-independent proteasome substrates were used to stratify inhibitors that emerged from the screen. N^2,N^4-dibenzylquinazoline-2,4-diamine (DBeQ) was identified as a selective, potent, reversible, and ATP-competitive p97 inhibitor. DBeQ blocks multiple processes that have been shown by RNAi to depend on p97, including degradation of ubiquitin fusion degradation and endoplasmic reticulum-associated degradation pathway reporters, as well as autophagosome maturation. DBeQ also potently inhibits cancer cell growth and is more rapid than a proteasome inhibitor at mobilizing the executioner caspases-3 and -7. Our results provide a rationale for targeting p97 in cancer therapy

Inactivation of VCP/ter94 Suppresses Retinal Pathology Caused by Misfolded Rhodopsin in Drosophila

The most common Rhodopsin (Rh) mutation associated with autosomal dominant retinitis pigmentosa (ADRP) in North America is the substitution of proline 23 by histidine (RhP23H). Unlike the wild-type Rh, mutant RhP23H exhibits folding defects and forms intracellular aggregates. The mechanisms responsible for the recognition and clearance of misfolded RhP23H and their relevance to photoreceptor neuron (PN) degeneration are poorly understood. Folding-deficient membrane proteins are subjected to Endoplasmic Reticulum (ER) quality control, and we have recently shown that RhP23H is a substrate of the ER–associated degradation (ERAD) effector VCP/ter94, a chaperone that extracts misfolded proteins from the ER (a process called retrotranslocation) and facilitates their proteasomal degradation. Here, we used Drosophila, in which Rh1P37H (the equivalent of mammalian RhP23H) is expressed in PNs, and found that the endogenous Rh1 is required for Rh1P37H toxicity. Genetic inactivation of VCP increased the levels of misfolded Rh1P37H and further activated the Ire1/Xbp1 ER stress pathway in the Rh1P37H retina. Despite this, Rh1P37H flies with decreased VCP function displayed a potent suppression of retinal degeneration and blindness, indicating that VCP activity promotes neurodegeneration in the Rh1P37H retina. Pharmacological treatment of Rh1P37H flies with the VCP/ERAD inhibitor Eeyarestatin I or with the proteasome inhibitor MG132 also led to a strong suppression of retinal degeneration. Collectively, our findings raise the possibility that excessive retrotranslocation and/or degradation of visual pigment is a primary cause of PN degeneration

Towards automated crystallographic structure refinement with phenix.refine

phenix.refine is a program within the PHENIX package that supports crystallographic structure refinement against experimental data with a wide range of upper resolution limits using a large repertoire of model parameterizations. This paper presents an overview of the major phenix.refine features, with extensive literature references for readers interested in more detailed discussions of the methods

Influence of several extracellular matrix components in primary cultures of bovine mammary epithelial cells

International audienc

Performances comparées de piles au lithium pour quelques fluorures de graphite

info:eu-repo/semantics/nonPublishe