Endonuclease Fingerprinting of Plasmids Mediating Gentamicin Resistance in an Outbreak of Hospital Infections

Rb, Davey; Pittard, J

doi:10.1038/icb.1980.32

Cited by 11 publications

(5 citation statements)

References 3 publications

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“…5B was performed. The binding of E-HPR was unaffected by prazosin at concentrations higher than the one required to completely occupy ␣ 1 -adrenergic receptors (29). Similar results were obtained with the ␣ 2 -adrenergic receptor ligands, yohimbine and clonidine, with propranolol, a ␤-adrenergic receptor ligand, and with the D 2 dopamine receptor antagonist quinpirole (Fig.…”

Section: The Plasma Membrane Estrogen Receptor Is a Catecholaminergicsupporting

confidence: 74%

Nongenomic actions of estrogens and xenoestrogens by binding at a plasma membrane receptor unrelated to estrogen receptor α and estrogen receptor β

Nadal

Ropero²,

Laribi³

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

338

261

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The molecular mechanism used by environmental chemicals to exert their hormone-like actions is still only partially resolved. Although it generally is accepted that xenoestrogens act at the genomic level by binding to intracellular estrogen receptors, we have shown here that they trigger nongenomic effects in pancreatic ␤ cells. Both xenoestrogens and the circulating hormone, 17␤-estradiol, bind with high affinity to a common membrane binding site unrelated to the intracellular estrogen receptors ER␣ and ER␤. This binding site is shared by dopamine, epinephrine, and norepinephrine and has the pharmacological profile of the ␥-adrenergic receptor. This study provides an outline of the membrane receptor involved in rapid xenoestrogen actions.pancreatic ␤ cells ͉ confocal microscopy ͉ intracellular calcium ͉ cell signaling X enoestrogens are compounds that present estrogenic effects but whose chemical structure does not necessarily resemble that of steroid hormones. They are found in fresh water and are likely responsible for the feminization of male fish in several rivers of the United Kingdom and the decreased reproduction success of alligators and turtles in Lake Apopka in Florida (1, 2). These manmade chemicals enter the body by ingestion or adsorption and mimic the genomic actions of estrogens (3) via intracellular estrogen receptors (4-6).Less attention has been paid to nongenomic actions of xenoestrogens. Several studies have described that xenoestrogens mimic 17␤-estradiol when they act on Ca 2ϩ and K ϩ channels in smooth muscle cells (7) as well as when they trigger prolactin release from rat pituitary tumor cells (8). Yet, a direct link between an estrogen membrane binding site (9) and xenoestrogen actions is still a matter of debate. Moreover, despite the great number of studies about nongenomic actions of estrogens, a clear outline of the membrane receptor involved is still elusive.We have chosen three widely used xenoestrogens for our study: bisphenol-A (BPA), which is found in the content of canned food, dental sealants, and composites; diethylstilbestrol (DES), a synthetic estrogen used between the 1940s and the 1970s to prevent miscarriages; and the well-known pesticide (3,(10)(11)(12). We have focused our research on the effect of these agents on the signaling system of pancreatic ␤ cells, which are fundamental for the endocrine pancreas function. ␤ cells, which are situated within the islet of Langerhans, are responsible for insulin secretion after an increase of blood glucose. A dysfunction of this particular type of cells causes the widespread pathology diabetes mellitus. An estrogen binding site at the plasma membrane of pancreatic ␤ cells has been described (13). Once 17␤-estradiol binds to this site, cGMP increases, activating protein kinase G, which phosphorylates ATPdependent potassium channels (K ATP ), depolarizing the plasma membrane, and enhancing intracellular Ca 2ϩ concentration ([Ca 2ϩ ] i ) signals. As a consequence, insulin secretion is increased (13, 14).Here, we show that acute no...

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Section: The Plasma Membrane Estrogen Receptor Is a Catecholaminergicsupporting

confidence: 74%

Nongenomic actions of estrogens and xenoestrogens by binding at a plasma membrane receptor unrelated to estrogen receptor α and estrogen receptor β

Nadal

Ropero²,

Laribi³

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

338

261

View full text Add to dashboard Cite

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“…Agprse gel electrophoresis. The procedures used for the isolation of plasmid DNA and for examination of this plasmid DNA by agarose gel electrophoresis were those described by Davey and Pittard (9).…”

Section: Methodsmentioning

confidence: 99%

Plasmid-controlled resistance to copper in Escherichia coli

Tetaz¹,

Luke²

1983

J Bacteriol

165

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The copper resistance of a strain of Escherichia coli isolated from the effluent of a piggery where pigs were fed a diet supplemented with copper sulfate was controlled by a conjugative 78-megadalton plasmid designated pRJ1004. Plasmid pRJ1004 exhibited surface exclusion and incompatibility with standard plasmids belonging to incompatibility groups I1 and K. Sensitive strains of E. coli K-12 were unable to form colonies on nutrient agar containing more than 4 mM copper, whereas transconjugants which harbored pRJ1004 were able to form colonies on medium containing up to 20 mM copper.

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“…Resiction endonudease digests. DNA was digested with the enzymes HindIlI and PstI and analyzed by standard methods of gel electrophoresis under the conditions previously described (10).…”

Section: Methodsmentioning

confidence: 99%

Construction from Mu d1 (lac Apr) lysogens of lambda bacteriophage bearing promoter-lac fusions: isolation of lambda ppheA-lac

Gowrishankar¹,

Pittard²

1982

J Bacteriol

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Bacteriophage Mu d1 (lac Aprr) was used to obtain strains of Escherichia coli K-12 in which the lac genes are expressed from the promoter of pheA, the structural gene for the enzyme chorismate mutase P-prephenate-dehydratase. A derivative of bacteriophage lambda which carries the pheA-lac fusion was prepared; the method used is generally applicable for the construction, from Mu dl lysogens, of specialized transducing lambda phage carrying the promoter-lac fusions. A restriction enzyme cleavage map of lambda ppheA-lac for the enzymes HindIII and PstI is presented.

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Endonuclease Fingerprinting of Plasmids Mediating Gentamicin Resistance in an Outbreak of Hospital Infections

Cited by 11 publications

References 3 publications

Nongenomic actions of estrogens and xenoestrogens by binding at a plasma membrane receptor unrelated to estrogen receptor α and estrogen receptor β

Nongenomic actions of estrogens and xenoestrogens by binding at a plasma membrane receptor unrelated to estrogen receptor α and estrogen receptor β

Plasmid-controlled resistance to copper in Escherichia coli

Construction from Mu d1 (lac Apr) lysogens of lambda bacteriophage bearing promoter-lac fusions: isolation of lambda ppheA-lac

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