A constitutively active mutant beta 2-adrenergic receptor is constitutively
desensitized and phosphorylated
G. Pei, P. Samama, M. Lohse, M. Wang, J. Codina, and R. Lefkowitz. Proc Natl Acad Sci U S A, 91 (7):
2699-702(March 1994)Pei, G Samama, P Lohse, M Wang, M Codina, J Lefkowitz, R J HL16037/HL/NHLBI
NIH HHS/United States Research Support, U.S. Gov't, P.H.S. United
states Proceedings of the National Academy of Sciences of the United
States of America Proc Natl Acad Sci U S A. 1994 Mar 29;91(7):2699-702..
Abstract
The beta 2-adrenergic receptor (beta 2AR) can be constitutively activated
by mutations in the third intracellular loop. Whereas the wild-type
receptor exists predominantly in an inactive conformation (R) in
the absence of agonist, the mutant receptor appears to spontaneously
adopt an active conformation (R*). We now demonstrate that not only
is the mutant beta 2AR constitutively active, it is also constitutively
desensitized and down-regulated. To assess whether the mutant receptor
can constitutively engage a known element of the cellular desensitization
machinery, the receptor was purified and reconstituted into phospholipid
vesicles. These preparations retained the essential properties of
the constitutively active mutant receptor: agonist-independent activity
to stimulate guanine nucleotide-binding protein (Gs)-GTPase and
agonist-specific increase in binding affinity. Moreover, the purified
mutant receptor, in the absence of agonist, was phosphorylated by
recombinant beta AR-specific kinase (beta ARK) in a fashion comparable
to the agonist-occupied wild-type receptor. Thus, the conformation
of the mutated receptor is equivalent to the active conformation
(R*), which stimulates Gs protein and is identical to the beta ARK
substrate.
Pei, G Samama, P Lohse, M Wang, M Codina, J Lefkowitz, R J HL16037/HL/NHLBI
NIH HHS/United States Research Support, U.S. Gov't, P.H.S. United
states Proceedings of the National Academy of Sciences of the United
States of America Proc Natl Acad Sci U S A. 1994 Mar 29;91(7):2699-702.
%0 Journal Article
%1 Pei1994
%A Pei, G.
%A Samama, P.
%A Lohse, M.
%A Wang, M.
%A Codina, J.
%A Lefkowitz, R. J.
%D 1994
%J Proc Natl Acad Sci U S A
%K *Mutation *Signal Acid Adrenergic Amino Animals Assay CHO Cricetinae Data Dose-Response Drug Expression GTP Gene Isoproterenol/pharmacology Molecular Phosphohydrolases/analysis Phosphorylation Proteins/metabolism Radioligand Recombinant Regulation Relationship, Sequence Transduction beta-2/drug beta-Agonists effects/genetics/*metabolism Receptor Cell
%N 7
%P 2699-702
%T A constitutively active mutant beta 2-adrenergic receptor is constitutively
desensitized and phosphorylated
%U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=7908440
%V 91
%X The beta 2-adrenergic receptor (beta 2AR) can be constitutively activated
by mutations in the third intracellular loop. Whereas the wild-type
receptor exists predominantly in an inactive conformation (R) in
the absence of agonist, the mutant receptor appears to spontaneously
adopt an active conformation (R*). We now demonstrate that not only
is the mutant beta 2AR constitutively active, it is also constitutively
desensitized and down-regulated. To assess whether the mutant receptor
can constitutively engage a known element of the cellular desensitization
machinery, the receptor was purified and reconstituted into phospholipid
vesicles. These preparations retained the essential properties of
the constitutively active mutant receptor: agonist-independent activity
to stimulate guanine nucleotide-binding protein (Gs)-GTPase and
agonist-specific increase in binding affinity. Moreover, the purified
mutant receptor, in the absence of agonist, was phosphorylated by
recombinant beta AR-specific kinase (beta ARK) in a fashion comparable
to the agonist-occupied wild-type receptor. Thus, the conformation
of the mutated receptor is equivalent to the active conformation
(R*), which stimulates Gs protein and is identical to the beta ARK
substrate.
@article{Pei1994,
abstract = {The beta 2-adrenergic receptor (beta 2AR) can be constitutively activated
by mutations in the third intracellular loop. Whereas the wild-type
receptor exists predominantly in an inactive conformation (R) in
the absence of agonist, the mutant receptor appears to spontaneously
adopt an active conformation (R*). We now demonstrate that not only
is the mutant beta 2AR constitutively active, it is also constitutively
desensitized and down-regulated. To assess whether the mutant receptor
can constitutively engage a known element of the cellular desensitization
machinery, the receptor was purified and reconstituted into phospholipid
vesicles. These preparations retained the essential properties of
the constitutively active mutant receptor: agonist-independent activity
[to stimulate guanine nucleotide-binding protein (Gs)-GTPase] and
agonist-specific increase in binding affinity. Moreover, the purified
mutant receptor, in the absence of agonist, was phosphorylated by
recombinant beta AR-specific kinase (beta ARK) in a fashion comparable
to the agonist-occupied wild-type receptor. Thus, the conformation
of the mutated receptor is equivalent to the active conformation
(R*), which stimulates Gs protein and is identical to the beta ARK
substrate.},
added-at = {2010-12-14T18:12:02.000+0100},
author = {Pei, G. and Samama, P. and Lohse, M. and Wang, M. and Codina, J. and Lefkowitz, R. J.},
biburl = {https://www.bibsonomy.org/bibtex/26c025b6758ae2d673c1796e5a89d3b14/pharmawuerz},
endnotereftype = {Journal Article},
interhash = {aee83b4e8562217a0789f1cae5969ad3},
intrahash = {6c025b6758ae2d673c1796e5a89d3b14},
issn = {0027-8424 (Print) 0027-8424 (Linking)},
journal = {Proc Natl Acad Sci U S A},
keywords = {*Mutation *Signal Acid Adrenergic Amino Animals Assay CHO Cricetinae Data Dose-Response Drug Expression GTP Gene Isoproterenol/pharmacology Molecular Phosphohydrolases/analysis Phosphorylation Proteins/metabolism Radioligand Recombinant Regulation Relationship, Sequence Transduction beta-2/drug beta-Agonists effects/genetics/*metabolism Receptor Cell},
month = {Mar 29},
note = {Pei, G Samama, P Lohse, M Wang, M Codina, J Lefkowitz, R J HL16037/HL/NHLBI
NIH HHS/United States Research Support, U.S. Gov't, P.H.S. United
states Proceedings of the National Academy of Sciences of the United
States of America Proc Natl Acad Sci U S A. 1994 Mar 29;91(7):2699-702.},
number = 7,
pages = {2699-702},
shorttitle = {A constitutively active mutant beta 2-adrenergic receptor is constitutively
desensitized and phosphorylated},
timestamp = {2010-12-14T18:22:42.000+0100},
title = {A constitutively active mutant beta 2-adrenergic receptor is constitutively
desensitized and phosphorylated},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=7908440},
volume = 91,
year = 1994
}