Coupling of the expressed alpha 1B-adrenergic receptor to the phospholipase C pathway in Xenopus oocytes. The role of Go.
Details
Serval ID
serval:BIB_65972D192AE8
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Coupling of the expressed alpha 1B-adrenergic receptor to the phospholipase C pathway in Xenopus oocytes. The role of Go.
Journal
Journal of Biological Chemistry
ISSN
0021-9258 (Print)
ISSN-L
0021-9258
Publication state
Published
Issued date
1993
Peer-reviewed
Oui
Volume
268
Number
10
Pages
7532-7537
Language
english
Abstract
alpha 1B-Adrenergic receptor mRNA was injected into Xenopus oocytes, resulting in a norepinephrine-evoked Cl- current. The response was proportional to norepinephrine concentration, blocked by prazosin, and dependent on intracellular Ca2+ derived from inositol trisphosphate-sensitive stores. Oocytes treated with 2 micrograms/ml pertussis toxin showed a time-dependent decrease of the norepinephrine response, taking up to 72 h to show an 80% decrease. Overnight treatment with 10 micrograms/ml pertussis toxin also resulted in 80% reduction. Responses to two other cloned receptors (M1-muscarinic and serotonin-1c) expressed in oocytes were also reduced 50% or more by 72 h of pertussis toxin treatment. Pertussis toxin labeling of the cloned Xenopus alpha o-subunit translated in vitro showed that it was a significantly poorer substrate for pertussis toxin than the two mammalian alpha o-subunits expressed and assayed under identical conditions. This unexpected biochemical behavior of the Xenopus alpha o-subunit is in agreement with the rather unusual treatment conditions required to observe the effects of pertussis toxin on the receptor-evoked Cl- current in the oocyte. Injection of mammalian heterotrimeric G(o) but not Gi3 significantly enhanced the norepinephrine-evoked Cl- current in oocytes. Injection of mixtures of anti-sense oligonucleotides to the Xenopus alpha o-subunit reduced the norepinephrine-evoked Cl- current by 60% within 24 h, compared with oocytes injected with the oligonucleotides encoding sense sequences. These studies indicate that the expressed alpha 1B-adrenergic receptor, like the native muscarinic receptor, utilizes G(o) to couple to the phospholipase C-mediated Cl- current in Xenopus oocytes.
Keywords
Animals, Cattle, Egtazic Acid/metabolism, Female, GTP-Binding Proteins/metabolism, Humans, Inositol 1,4,5-Trisphosphate/metabolism, Kinetics, Oocytes/enzymology, Pertussis Toxin, Receptors, Adrenergic, alpha/metabolism, Signal Transduction, Type C Phospholipases/metabolism, Virulence Factors, Bordetella/pharmacology, Xenopus laevis
Pubmed
Web of science
Create date
24/01/2008 12:05
Last modification date
20/08/2019 15:21