Evidence that a new enterotoxin of Escherichia coli which activates adenylate cyclase in eucaryotic target cells is not plasmid mediated
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منابع مشابه
Evidence that a new enterotoxin of Escherichia coli which activates adenylate cyclase in eucaryotic target cells is not plasmid mediated.
Escherichia coli SA53 produces a new enterotoxin that has a biological activity similar to that of E. coli heat-labile enterotoxin (LT) but is not neutralized by antiserum against LT or cholera enterotoxin. Strain SA53 contained two plasmids, pRB1 (69.2 +/- 4.3 megadaltons) and pRB2 (57.6 +/- 5.3 megadaltons). Studies were undertaken to determine whether either plasmid was required for producti...
متن کاملAction of Escherichia coli enterotoxin: adenylate cyclase behavior of intestinal epithelial cells in culture.
Heat-labile enterotoxin preparations obtained from two enteropathogenic strains of Escherichia coli of porcine and human origin were shown to stimulate adenylate cyclase activity of human embryonic intestinal epithelial cells in culture. Comparable results were also obtained when cholera toxin was used. The degree of enzyme stimulation was proportional to the concentration of enterotoxin. Simil...
متن کاملActivation of adenylate cyclase by heat-labile Escherichia coli enterotoxin. Evidence for ADP-ribosyltransferase activity similar to that of choleragen.
Highly purified, polymyxin-released, low molecular weight Escherichia coli heat-labile enterotoxin (LT) catalyzed the hydrolysis of NAD to ADP-ribose and nicotinamide. This NAD glycohydrolase activity was stimulated by dithiothreitol and was independent of cellular components. Nicotinamide formation was enhanced by arginine methyl ester > d-arginine congruent with l-arginine congruent with guan...
متن کاملCra-mediated regulation of Escherichia coli adenylate cyclase.
In Escherichia coli, expression of certain genes and operons, including the fructose operon, is controlled by Cra, the pleiotropic catabolite repressor/activator protein formerly known as FruR. In this study we have demonstrated that cra mutant strains synthesize 10-fold less cAMP than isogenic wild-type strains, specifically when grown in fructose-containing minimal media. The glucose-specific...
متن کاملType II heat-labile enterotoxin of Escherichia coli activates adenylate cyclase in human fibroblasts by ADP ribosylation.
Type II heat-labile enterotoxin (LT-II) from Escherichia coli causes characteristic morphological changes and accumulation of cyclic AMP in Y-1 adrenal cells, but it is not neutralized by antisera against choleragen (CT) or the classical type I heat-labile enterotoxin (LT-1) from E. coli. The action of purified LT-II on CT- and LT-I-responsive human fibroblasts was investigated and compared wit...
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ژورنال
عنوان ژورنال: Infection and Immunity
سال: 1983
ISSN: 0019-9567,1098-5522
DOI: 10.1128/iai.41.1.383-390.1983