Search results for "Shock proteins"
showing 10 items of 347 documents
Identification of the plant compound geraniin as a novel Hsp90 inhibitor
2013
Besides its function in normal cellular growth, the molecular chaperone heat shock protein 90 (Hsp90) binds to a large number of client proteins required for promoting cancer cell growth and/or survival. In an effort to discover new small molecules able to inhibit the Hsp90 ATPase and chaperoning activities, we screened, by a surface plasmon resonance assay, a small library including different plant polyphenols. The ellagitannin geraniin, was identified as the most promising molecule, showing a binding affinity to Hsp90α similar to that of 17-(allylamino)-17-demethoxygeldanamycin (17AGG). Geraniin was able to inhibit in vitro the Hsp90α ATPase activity in a dose−dependent manner, with an in…
The loss of muscle mass and sarcopenia: non hormonal intervention.
2011
Muscle aging is a key component of the increase in frailty in human populations. The generation of critical levels of power is a prerequisite to perform simple tasks of daily living, such as rising from a chair or climbing stairs. There is great scientific and social interest to determine which behaviors can lead to the maintenance of the muscle mass in young immobilized subjects and in the elderly. Several hormonal treatments have been proposed for the treatment of sarcopenia. However, the side effects associated to these treatments emphasize the need of finding non-toxic and non-hormonal treatments that help increase muscle strength, improve muscle function, and decrease the degree of dep…
Stress-70 proteins in marine mussel Mytilus galloprovincialis as biomarkers of environmental pollution: a field study.
2004
In the present work we have investigated levels of stress-70 proteins in the gills of mussel Mytilus galloprovincialis collected seasonally from subtidal rocky shores at 6 different sites of the Rovinj coastal area (Northern Adriatic, Croatia). 1-D analysis (SDS-PAGE) using monoclonal mouse antibodies anti-HSP70 detected two bands of stress-70 proteins, 70 and 72 kDa constitutively present during the year. 2-D analysis (IEF+SDS-PAGE) proved that the antibodies used detected HSP70 (pI 5.7–5.9) and HSP72 (pI 5.5–5.6). The quantification of stress-70 proteins was possible using 200 ng of external HSP70 protein standard included on every blot. Maximal levels of HSP72 and HSP70 were observed in …
The effects of treated effluents on the intensity of papillomatosis and HSP70 expression in roach.
2008
Epidermal papillomatosis in fish has been proposed as an indicator of environmental stress but experimental evidence of connection between contaminants and papillomatosis in fish is scarce. We studied changes in the intensity of epidermal papillomatosis and the expression of heat shock protein 70 (HSP70) in roach, Rutilus rutilus, exposed to treated pulp mill and municipal effluents. In male roach, the increase in papillomatosis intensity was higher in fish exposed to 15% than in fish exposed to 1.5% concentration of municipal effluent. No differences were observed in papillomatosis development in females, or in HSP70 expression. In all the experiments conducted, the increasing effect of ef…
Evidence for the attachment of Hsp150/Pir2 to the cell wall of Saccharomyces cerevisiae through disulfide bridges.
2001
Here we present evidence that Hsp150/Pir2, a member of the Pir family of cell wall proteins, can be extracted from the purified cell walls of Saccharomyces cerevisiae by treatment with beta-mercaptoethanol, demonstrating that at least part of this protein is attached to the cell wall through disulfide bridges. We also present evidence that Pir4, another member of this family, is partly secreted to the growth medium. Finally we propose a hypothesis to explain the relationship between the differently localized forms of particular members of the Pir family of cell wall proteins.
Concomitant cellular expression of heat shock regulated genes of hepatitis B virus surface antigen and of human growth hormone by a NIH-3T3 cell line.
1993
A plasmid carrying a DNA fragment of hepatitis B virus, coding for the pre-S2 and the entire S region of the surface antigen (HBsAg), placed under the control of the promoter of the human 70 kDa heat shock protein gene (hsp70), was introduced into Line 6, a recombinant cell line that was selected from NIH-3T3 cells previously transfected with a similar construct coding for the human growth hormone cDNA gene (chGH) and with the plasmid pEJ carrying the Ha-rasEJ activated cellular oncogene. The resulting cell line, EMS8, expressed: (1) hsp70/HBsAg and hsp70/hGH hybrid genes, (2) the human Ha-rasEJ oncogene, and (3) the neomycin resistance gene, the two last plasmid markers being used for cell…
Sea urchin coelomocytes as a novel cellular biosensor of environmental stress: a field study in the Tremiti Island Marine Protected Area, Southern Ad…
2007
The aim of the present study was to investigate on the suitability of the sea urchin as a sentinel organism for the assessment of the macro-zoobenthos health state in bio-monitoring programmes. A field study was carried out during two oceanographic campaigns using immuno-competent cells, the coelomocytes, from sea urchins living in a marine protected area. In particular, coelomocytes subpopulations ratio and heat shock protein 70 (HSC70) levels were measured in specimens of Paracentrotus lividus (Lamark, 1816) collected in two sampling sites, namely Pianosa and Caprara Islands, both belonging to the Tremiti Island Marine Protected Area (MPA) in the Southern Adriatic Sea, Italy. By density g…
Protective role of heat shock proteins in Parkinson's disease.
2010
Parkinson’s disease (PD) is the second most common neurodegenerative disease after Alzheimer’s disease. Despite a large amount of research, the pathogenetic mechanism of these diseases has not yet been clarified. Abnormal protein folding, oxidative stress, mitochondrial dysfunction, and apoptotic mechanisms have all been reported as causes of neurodegenerative diseases in association with neuroinflammatory mechanisms which, by generating deleterious molecules, could promote the cascade of events leading to neurodegeneration. Heat shock proteins (HSPs) play a central role in preventing protein misfolding and inhibiting apoptotic activity, and represent a class of proteins potentially involve…
Manganese effects on haematopoietic cells and circulating coelomocytes of Asterias rubens (Linnaeus)
2008
Abstract Manganese (Mn) is a naturally abundant metal in marine sediments where it mainly occurs as MnO 2 . During hypoxic conditions it is converted into a bioavailable state, Mn 2+ , and can reach levels that previously have shown effects on immune competent cells of the crustacean, Nephrops norvegicus . Here we investigated if Mn also affects circulating coelomocytes and their renewal in the common sea star, Asterias rubens , when exposed to concentrations of Mn that can be found in nature. When the sea stars were exposed to Mn it accumulated in the coelomic fluid and the number of circulating coelomocytes, in contrast to what was recorded in Nephrops , increased significantly. By using …
Sequence-Specific Repression of Cotranslational Translocation of the Hepatitis B Virus Envelope Proteins Coincides with Binding of Heat Shock Protein…
1997
AbstractThe large L envelope protein of the hepatitis B virus has the peculiar capacity to adopt two transmembrane topologies. The N-terminal preS domain of L initially remains in the cytosol while the S domain is cotranslationally inserted into the endoplasmic reticulum membrane. The preS region of about half of the L molecules is posttranslationally translocated to the lumenal space. We now demonstrate that the repression of cotranslational translocation of preS is conferred by a preS1-specific sequence. By analysis of L deletion mutants, the cytosolic anchorage determinant was mapped to amino acid sequence 70 to 94 of L. The intrinsic potential of this determinant to suppress cotranslati…