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B1 Bradykinin Receptor Homo-oligomers in Receptor Cell Surface Expression and Signaling: Effects of Receptor Fragments.

Kang, Dongsoo LU ; Gustafsson, Caroline; Mörgelin, Matthias LU and Leeb-Lundberg, Fredrik LU (2005) In Molecular Pharmacology 67(1). p.309-318
Abstract
The human B1 bradykinin receptor is an inducible and constitutively active G protein-coupled receptor that is involved in the inflammatory and pain responses to injury. Here, we investigated the role of B1 receptor homo-oligomerization in cell surface receptor expression. B1 receptors tagged with either the FLAG or hemagglutinin epitope were monitored immunologically and by radio-ligand binding, biotinylation, and phosphoinositide hydrolysis in human embryonic kidney 293 cells. Selective immunoprecipitation, immunoblotting, and immunoelectron microscopy with epitope-specific antibodies together provided evidence for constitutively formed cell surface receptor homo-oligomers. Truncation of the receptor from the N- and C-terminal ends... (More)
The human B1 bradykinin receptor is an inducible and constitutively active G protein-coupled receptor that is involved in the inflammatory and pain responses to injury. Here, we investigated the role of B1 receptor homo-oligomerization in cell surface receptor expression. B1 receptors tagged with either the FLAG or hemagglutinin epitope were monitored immunologically and by radio-ligand binding, biotinylation, and phosphoinositide hydrolysis in human embryonic kidney 293 cells. Selective immunoprecipitation, immunoblotting, and immunoelectron microscopy with epitope-specific antibodies together provided evidence for constitutively formed cell surface receptor homo-oligomers. Truncation of the receptor from the N- and C-terminal ends indicated that the epitope for oligomerization seems to be located between Leu26 on top of transmembrane helix 1 and Val71 at the bottom of helix 2. A receptor construct terminating at Asp134 at the bottom of helix 3, B1stop135, was expressed in the cell. It is interesting that this construct behaved as a dominant-negative mutant by competitively preventing formation of intact B1 receptor homo-oligomers, and redistributing B1 receptors from the cell surface to a common intracellular compartment. In contrast, expression of a construct containing the residues downstream of Asp134, B1del(2-134), was inactive in this regard. Together, these results are consistent with a mechanism where constitutive B1 receptor homooligomerization is required for expression of receptors on the cell surface and subsequent constitutive receptor signaling. This may be a novel mechanism by which the cell regulates the presentation of this constitutively highly active receptor at various stages of injury. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Molecular Pharmacology
volume
67
issue
1
pages
309 - 318
publisher
American Society for Pharmacology and Experimental Therapeutics
external identifiers
  • pmid:15492119
  • wos:000225865200035
  • scopus:11244319585
ISSN
1521-0111
DOI
10.1124/mol.104.002840
language
English
LU publication?
yes
id
e89a0038-923c-49fc-b45f-4806e76022e9 (old id 129779)
date added to LUP
2007-07-16 14:23:25
date last changed
2017-01-01 05:13:59
@article{e89a0038-923c-49fc-b45f-4806e76022e9,
  abstract     = {The human B1 bradykinin receptor is an inducible and constitutively active G protein-coupled receptor that is involved in the inflammatory and pain responses to injury. Here, we investigated the role of B1 receptor homo-oligomerization in cell surface receptor expression. B1 receptors tagged with either the FLAG or hemagglutinin epitope were monitored immunologically and by radio-ligand binding, biotinylation, and phosphoinositide hydrolysis in human embryonic kidney 293 cells. Selective immunoprecipitation, immunoblotting, and immunoelectron microscopy with epitope-specific antibodies together provided evidence for constitutively formed cell surface receptor homo-oligomers. Truncation of the receptor from the N- and C-terminal ends indicated that the epitope for oligomerization seems to be located between Leu26 on top of transmembrane helix 1 and Val71 at the bottom of helix 2. A receptor construct terminating at Asp134 at the bottom of helix 3, B1stop135, was expressed in the cell. It is interesting that this construct behaved as a dominant-negative mutant by competitively preventing formation of intact B1 receptor homo-oligomers, and redistributing B1 receptors from the cell surface to a common intracellular compartment. In contrast, expression of a construct containing the residues downstream of Asp134, B1del(2-134), was inactive in this regard. Together, these results are consistent with a mechanism where constitutive B1 receptor homooligomerization is required for expression of receptors on the cell surface and subsequent constitutive receptor signaling. This may be a novel mechanism by which the cell regulates the presentation of this constitutively highly active receptor at various stages of injury.},
  author       = {Kang, Dongsoo and Gustafsson, Caroline and Mörgelin, Matthias and Leeb-Lundberg, Fredrik},
  issn         = {1521-0111},
  language     = {eng},
  number       = {1},
  pages        = {309--318},
  publisher    = {American Society for Pharmacology and Experimental Therapeutics},
  series       = {Molecular Pharmacology},
  title        = {B1 Bradykinin Receptor Homo-oligomers in Receptor Cell Surface Expression and Signaling: Effects of Receptor Fragments.},
  url          = {http://dx.doi.org/10.1124/mol.104.002840},
  volume       = {67},
  year         = {2005},
}