Linked Life Data

8232231

Source:http://linkedlifedata.com/resource/pubmed/id/8232231

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1993-11-29
pubmed:abstractText
A cAMP-dependent reporter gene has been used in transiently transfected human choriocarcinoma (JEG-3) cells to examine the second messenger coupling of the human alpha 2-adrenergic receptor subtypes. The reporter gene consists of a cAMP response element linked to the gene for chloramphenicol acetyltransferase (CAT). Plasmids encoding the alpha 2-C10 (alpha 2A), alpha 2-C2 (alpha 2B), or alpha 2-C4 (alpha 2C) receptor subtypes were co-transfected with a plasmid containing the reporter gene, and the ability of alpha 2 receptor agonists to influence forskolin-stimulated CAT expression was examined. For alpha 2-C10, agonists had a biphasic effect on forskolin-stimulated CAT expression. Thus, low (nanomolar) concentrations of agonist inhibited CAT expression by approximately 60%, whereas high (micromolar) concentrations reversed this inhibition and could even potentiate CAT expression by as much as 140%. A significantly different pattern of coupling was observed for the other alpha 2 receptor subtypes. For alpha 2-C4, agonists only inhibited forskolin-stimulated CAT expression, whereas for alpha 2-C2 only potentiation of expression was seen. Each of these responses was specifically blocked by alpha 2- but not alpha 1- or beta-adrenergic receptor antagonists. For alpha 2-C4, the inhibition of forskolin-stimulated CAT expression was prevented by pretreatment of the cells with pertussis toxin. This was also true for the inhibition obtained with alpha 2-C10. The potentiation of CAT expression, however, was not prevented by pertussis toxin pretreatment in cells transfected with either alpha 2-C2 or alpha 2-C10. In this transient expression system, each alpha 2-adrenergic receptor subtype had access to the same complement of G proteins, adenylyl cyclase, and other second messengers. It would appear, therefore, that the potential for the activation of unique intracellular responses exists even among closely related receptor subtypes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0026-895X
pubmed:author
pubmed:issnType
Print
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
802-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:8232231-Adenylate Cyclase Toxin, pubmed-meshheading:8232231-Animals, pubmed-meshheading:8232231-CHO Cells, pubmed-meshheading:8232231-Chloramphenicol O-Acetyltransferase, pubmed-meshheading:8232231-Choriocarcinoma, pubmed-meshheading:8232231-Cricetinae, pubmed-meshheading:8232231-Cyclic AMP, pubmed-meshheading:8232231-Forskolin, pubmed-meshheading:8232231-Gene Expression, pubmed-meshheading:8232231-Gene Expression Regulation, Neoplastic, pubmed-meshheading:8232231-Humans, pubmed-meshheading:8232231-Kinetics, pubmed-meshheading:8232231-Pertussis Toxin, pubmed-meshheading:8232231-Receptors, Adrenergic, alpha-2, pubmed-meshheading:8232231-Second Messenger Systems, pubmed-meshheading:8232231-Stimulation, Chemical, pubmed-meshheading:8232231-Transfection, pubmed-meshheading:8232231-Tumor Cells, Cultured, pubmed-meshheading:8232231-Virulence Factors, Bordetella
pubmed:year
1993
pubmed:articleTitle
Selective coupling of alpha 2-adrenergic receptor subtypes to cyclic AMP-dependent reporter gene expression in transiently transfected JEG-3 cells.
pubmed:affiliation
Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson 85721.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't