- Villeurbanne, France
carole kretz
Université Claude Bernard Lyon 1, Biology, Faculty Member
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ABSTRACT
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Research Interests: Kinetics, Gene expression, Biological Sciences, Cell line, Humans, and 15 moreReactive Oxygen Species, Mice, Female, Animals, Glutathione Peroxidase, Phosphorylation, Biochemical, CHEMICAL SCIENCES, Carcinoma, Tumor necrosis factor-alpha, Heat Shock Proteins, Recombinant Proteins, Breast Neoplasms, fluorescent dyes, and Medical and Health Sciences
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We report here that both kappa B-dependent transactivation of a reporter gene and NF-kappa B activation in response to tumor necrosis factor (TNF alpha) or H2O2 treatments are deficient in human T47D cell transfectants that overexpress... more
We report here that both kappa B-dependent transactivation of a reporter gene and NF-kappa B activation in response to tumor necrosis factor (TNF alpha) or H2O2 treatments are deficient in human T47D cell transfectants that overexpress seleno-glutathione peroxidase (GSHPx). These cells feature low reactive oxygen species (ROS) levels and decreased intracellular ROS burst in response to TNF alpha treatment. Decreased ROS levels and NF-kappa B activation were likely to result from GSHPx increment since these phenomena were no longer observed when GSHPx activity was reduced by selenium depletion. The cellular contents of the two NF-kappa B subunits (p65 and p50) and of the inhibitory subunit I kappa B-alpha were unaffected by GSHPx overexpression, suggesting that increased GSHPx activity interfered with the activation, but not the synthesis or stability, of Nf-kappa B. Nuclear translocation of NF-kappa B as well as I kappa B-alpha degradation were inhabited in GSHPx-overexpressing cell...
Research Interests: Cell Biology, Oxidative Stress, Gene expression, Biological Sciences, DNA, and 13 moreCell line, Humans, Reactive Oxygen Species, NF-kappa B, Glutathione Peroxidase, Phosphorylation, Hydrogen Peroxide, Cell nucleus, Tumor necrosis factor-alpha, The cell, Transfection, DNA binding proteins, and Medical and Health Sciences
We previously found that the NF-κB transcription factor is activated during the recovery period after heat shock; moreover, we demonstrated that NF-κB is essential for cell survival after heat shock by activating autophagy, a mechanism... more
We previously found that the NF-κB transcription factor is activated during the recovery period after heat shock; moreover, we demonstrated that NF-κB is essential for cell survival after heat shock by activating autophagy, a mechanism that probably helps the cell to cope with hyperthermic stress through clearance of damaged proteins. In this study, we analyze the involvement of NF-κB in basal and heat-stress-induced protein quality control, by comparing the level of multiubiquitylated and/or aggregated proteins, and proteasome and autophagic activity in NF-κB-competent and NF-κB-incompetent cells. We show that NF-κB has only a minor role in basal protein quality control, where it modulates autophagosome maturation. By contrast, NF-κB is shown to be a key player in protein quality control after hyperthermia. Indeed, NF-κB-incompetent cells show highly increased levels of multiubiquitylated and/or aggregated proteins and aggresome clearance defects; a phenotype that disappears when N...
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Regulation of protein functions can be achieved by posttranslational protein modifications. One of the most studied modifications has been conjugation to ubiquitin, which mainly targets substrate proteins for degradation by the 26 S... more
Regulation of protein functions can be achieved by posttranslational protein modifications. One of the most studied modifications has been conjugation to ubiquitin, which mainly targets substrate proteins for degradation by the 26 S proteasome. Recently, SUMO/sentrin, a ubiquitin-like protein has been characterized. This evolutionary conserved protein is conjugated to specific proteins in a way similar, but not identical, to ubiquitin and seems also to be involved in the regulation of protein localization or function. An increasing number of SUMO/sentrin substrates are currently described. We focus here on three major substrates of modification by SUMO: RanGAP1, PML, and I(kappa)B(alpha) proteins. These different examples illustrate how SUMO conjugation may be involved in the control of the level of critical proteins within the cell or in the modulation of subcellular localization and nucleocytoplasmic trafficking.Key words: protein modification, NF-(kappa)B, I(kappa)B, protein transport, nucleus, RanGAP1, PML.
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Hsp27 and alphaB-crystallin are molecular chaperones that are constitutively expressed in several mammalian cells, particularly in pathological conditions. These proteins share functions as diverse as protection against toxicity mediated... more
Hsp27 and alphaB-crystallin are molecular chaperones that are constitutively expressed in several mammalian cells, particularly in pathological conditions. These proteins share functions as diverse as protection against toxicity mediated by aberrantly folded proteins or oxidative-inflammation conditions. In addition, these proteins share anti-apoptotic properties and are tumorigenic when expressed in cancer cells. This review summarizes the current knowledge about Hsp27 and alphaB-crystallin and the implications, either positive or deleterious, of these proteins in pathologies such as neurodegenerative diseases, myopathies, asthma, cataracts and cancers. Approaches towards therapeutic strategies aimed at modulating the expression and/or the activities of Hsp27 and alphaB-crystallin are presented.