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
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
Author(s)
Blitzer R.D., Omri G., De Vivo M., Carty D.J., Premont R.T., Codina J., Birnbaumer L., Cotecchia S., Caron M.G., Lefkowitz R.J., Landau E.M., Iyengar R.
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 11:05
Last modification date
20/08/2019 14:21
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