Search results for "Shock"
showing 10 items of 1248 documents
Enhanced susceptibility to cytotoxic T lymphocytes without increase of MHC class I antigen expression after conditional overexpression of heat shock …
1999
Antigenic peptides have been found associated with heat shock proteins (HSP) including cytoplasmic HSP70 and heat shock cognate protein 70 as well as the endoplasmic reticulum-resident glucose-regulated protein 94. Recently, HSP70 transfection has been reported to increase MHC class I cell surface expression and antigen presentation on mouse melanoma B16 cells (Wells et al., Int. Immunol. 1998. 10: 609). To analyze the effect of HSP70 on MHC class I cell surface expression and lysability of target cells we transfected a human melanoma cell line with the rat Hsp70-1 gene using the Tet-On system for conditional overexpression of HSP70. Induction of HSP70 did not increase cell surface expressi…
Induction of DNA strand breaks and expression of HSP70 and GRP78 homolog by cadmium in the marine sponge Suberites domuncula
1998
The marine sponge Suberites domuncula was used as a bioindicator to study the effects of cadmium on the occurrence of DNA strand breakage and on the induction of the expression of the stress biomarkers, heat shock protein 70 (HSP70) and glucose-regulated protein 78 (GRP78) homolog. The cDNA encoding GRP78 homolog from S. domuncula was isolated and characterized. The GRP78 cDNA has a length of 2.1 kb and displays characteristic features of the HSP70 family ; it encodes an aa sequence of M-r 72, 000. Exposure of S. domuncula to 1 mg/L of cadmium chloride for 24 h caused a strong(16.6-fold) increase in cadmium content to 7.7 mu g/g wet weight of sponge tissue ; after an incubation period of 6 …
Correlation between the level of the potential biomarker, heat-shock protein, and the occurrence of DNA damage in the dab, Limanda limanda: a field s…
2000
In the present study, heat-shock protein of M-r 70 kDa (HSP70), a marker of cellular stress response, was validated as a potential biomarker under field conditions. The dab, Limanda limanda (female, size greater than or equal to 25 cm, spawning maturity stage 2) was used as the indicator organism. The data on HSP level were correlated with the occurrence of DNA damage, measured in the same specimens of L. limanda, to prove the usefulness of the method. The area under investigation was the North Sea. Four locations were selected: station N01, close to Heligoland, in the North Sea; station N04 at the Dogger Bank; station N06 at the Firth of Forth; and station G08 in the English Channel. Ten a…
Developmental control of the heat-shock stress regulon in Streptomyces coelicolor
1995
In the differentiating eubacterium Streptomyces coelicolor, nutritional imbalances activate a developmental programme which involves the heat-shock stress regulon. In liquid batch cultures, the growth curve could be separated into four components: rapid growth 1 (RG1), transition (T), rapid growth 2 (RG2) and stationary (S). Patterns of gene expression in cultures subjected to heat shock in various phases were recorded on two-dimensional gels and analysed using advanced statistical methods. The responses of all heat-shock proteins (HSPs) were highly dependent upon the growth phase, thus demonstrating that the four phases of growth were physiologically distinct. For many HSPs, the levels of …
Cloning and sequencing of the dnaK region of Streptomyces coelicolor A3(2)
1993
Abstract The dnaK homologue of Streptomyces coelicolor A3(2) strain M145 has been cloned and sequenced. Nucleotide sequence analysis of a 2.5-kb region revealed an open reading frame (ORF) encoding a predicted DnaK protein of 618 amino acids (Mr = 66 274). The dnaK coding sequence displays extreme codon bias and shows a strong preference for CGY and GGY, for Arg and Gly codons, respectively. The predicted DnaK sequence has a high Lys:Arg ratio which is not typical of streptomycete proteins. The region immediately downstream from dnaK contains an ORF for a GrpE-like protein; the predicted start codon of grpE overlaps the last two codons of dnaK, indicating that the two genes are translationa…
Staphylococcal food poisoning case and molecular analysis of toxin genes in Staphylococcus aureus strains isolated from food in Sicily, Italy.
2014
A case of staphylococcal food poisoning was observed in two individuals of the same family after consumption of primosale, a semiripened sheep cheese produced in Sicily. Staphylococcus aureus isolated from the cheese produced enterotoxin C (SEC) and carried both the enterotoxin C (sec) and the toxic shock syndrome toxin (tsst-1) gene. Following this case, an extensive survey was conducted on 971 food samples (raw milk, cheese, meat, and food preparations). S. aureus was detected in 102 of 971 food samples, from all types of food with the exception of ricotta cheese. The tsst-1 gene was present in 42% of the strains, either alone or in combination with other toxin genes. The enterotoxin C ge…
The Chaperone Activity of Clusterin is Dependent on Glycosylation and Redox Environment
2014
Background/Aims: Clusterin (CLU), also known as Apolipoprotein J (ApoJ) is a highly glycosylated extracellular chaperone. In humans it is expressed from a broad spectrum of tissues and related to a plethora of physiological and pathophysiological processes, such as Alzheimer's disease, atherosclerosis and cancer. In its dominant form it is expressed as a secretory protein (secreted CLU, sCLU). During its maturation, the sCLU-precursor is N-glycosylated and cleaved into an α- and a β-chain, which are connected by five symmetrical disulfide bonds. Recently, it has been demonstrated that besides the predominant sCLU, rare intracellular CLU forms are expressed in stressed cells. Since these for…
Cold stress defense in the freshwater sponge Lubomirskia baicalensis
2007
The endemic freshwater sponge Lubomirskia baicalensis lives in Lake Baikal in winter (samples from March have been studied) under complete ice cover at near 0 degrees C, and in summer in open water at 17 degrees C (September). In March, specimens show high metabolic activity as reflected by the production of gametes. L. baicalensis lives in symbiosis with green dinoflagellates, which are related to Gymnodinium sanguineum. Here we show that these dinoflagellates produce the toxin okadaic acid (OA), which is present as a free molecule as well as in a protein-bound state. In metazoans OA inhibits both protein phosphatase-2A and protein phosphatase-1 (PP1). Only cDNA corresponding to PP1 could …
Evolutionary relationships of Metazoa within the eukaryotes based on molecular data from Porifera
1999
Recent molecular data provide strong support for the view that all metazoan phyla, including Porifera, are of monophyletic origin. The relationship of Metazoa, including the Porifera, to Plantae, Fungi and unicellular eukaryotes has only rarely been studied by using cDNAs coding for proteins. Sequence data from rDNA suggested a relationship of Porifera to unicellular eukaryotes (choanoflagellates). However, ultrastructural studies of choanocytes did not support these findings. In the present study, we compared amino acid sequences that are found in a variety of metazoans (including sponges) with those of Plantae, Fungi and unicellular eukaryotes, to obtain an answer to this question. We use…
Expression of a plant serine O-acetyltransferase inSaccharomyces cerevisiae confers osmotic tolerance and creates an alternative pathway for cysteine…
2004
Screening of a sugar beet (Beta vulgaris cv. Dita) cDNA library for clones able to confer osmotic tolerance to the osmosensitive gpd1 mutant of Saccharomyces cerevisiae identified a novel serine O-acetyltransferase (BvSAT; EC 2.3.1.30). This enzyme is involved in cysteine biosynthesis in plants and bacteria, producing O-acetylserine, which is converted into cysteine in a reaction catalysed by O-acetylserine sulphydrylase (EC 4.2.99.8). This pathway is not conserved in yeast, where cysteine is synthesized in a four-step pathway starting with homoserine and having O-acetylhomoserine, homocysteine and cystathionine as intermediates. Expression of BvSAT in yeast takes advantage of the activity …