View in EDS

Helix 8 Plays a Crucial Role in Bradykinin B2 Receptor Trafficking and Signaling.

Saved in:
Bibliographic Details
Title: Helix 8 Plays a Crucial Role in Bradykinin B2 Receptor Trafficking and Signaling.
Authors: Feierler, Jens1, Wirth, Markus1, Welte, Benjamin1, Schüssler, Steffen1, Jochum, Marianne1, Faussner, Alexander1 alexander.faussner@med.uni-muenchen.de
Source: Journal of Biological Chemistry. 12/16/2011, Vol. 286 Issue 50, p43282-43293. 12p.
Subjects: Bradykinin receptors, G proteins, Guanine nucleotide exchange factors, G protein-coupled receptor kinases, Amino acids, Cell membranes, Phosphorylation
Abstract: Upon activation the human bradykinin B2 receptor (B2R) acts as guanine nucleotide exchange factor for the G proteins Gq/11 and Gi. Thereafter, it gets phosphorylated by G protein-coupled receptor kinases (GRKs) and recruits β-arrestins, which block further G protein activation and promote B2R internalization via clathrin-coated pits. As for most G protein-coupled receptors of family A, an intracellular helix 8 after transmembrane domain 7 is also predicted for the B2R. We show here that disruption of helix 8 in the B2R by either C-terminal truncation or just by mutation of a central amino acid (Lys-315) to a helix-breaking proline resulted in strong reduction of surface expression. Interestingly, this malfunction could be overcome by the addition of the membrane-permeable B2R antagonist JSM10292, suggesting that helix 8 has a general role for conformational stabilization that can be accounted for by an appropriate antagonist. Intriguingly, an intact helix 8, but not the C terminus with its phosphorylation sites, was indispensable for receptor sequestration and for interaction of the B2R with GRK2/3 and β-arrestin2 as shown by co-immunoprecipitation. Recruitment of β-arrestin1, however, required the presence of the C terminus. Taken together, our results demonstrate that helix 8 of the B2R plays a crucial role not only in efficient trafficking to the plasma membrane or the activation of G proteins but also for the interaction of the B2R with GRK2/3 and β-arrestins. Additional data obtained with chimera of B2R with other G protein-coupled receptors of family A suggest that helix 8 might have similar functions in other GPCRs as well. [ABSTRACT FROM AUTHOR]
Copyright of Journal of Biological Chemistry is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
Abstract:Upon activation the human bradykinin B2 receptor (B2R) acts as guanine nucleotide exchange factor for the G proteins Gq/11 and Gi. Thereafter, it gets phosphorylated by G protein-coupled receptor kinases (GRKs) and recruits β-arrestins, which block further G protein activation and promote B2R internalization via clathrin-coated pits. As for most G protein-coupled receptors of family A, an intracellular helix 8 after transmembrane domain 7 is also predicted for the B2R. We show here that disruption of helix 8 in the B2R by either C-terminal truncation or just by mutation of a central amino acid (Lys-315) to a helix-breaking proline resulted in strong reduction of surface expression. Interestingly, this malfunction could be overcome by the addition of the membrane-permeable B2R antagonist JSM10292, suggesting that helix 8 has a general role for conformational stabilization that can be accounted for by an appropriate antagonist. Intriguingly, an intact helix 8, but not the C terminus with its phosphorylation sites, was indispensable for receptor sequestration and for interaction of the B2R with GRK2/3 and β-arrestin2 as shown by co-immunoprecipitation. Recruitment of β-arrestin1, however, required the presence of the C terminus. Taken together, our results demonstrate that helix 8 of the B2R plays a crucial role not only in efficient trafficking to the plasma membrane or the activation of G proteins but also for the interaction of the B2R with GRK2/3 and β-arrestins. Additional data obtained with chimera of B2R with other G protein-coupled receptors of family A suggest that helix 8 might have similar functions in other GPCRs as well. [ABSTRACT FROM AUTHOR]
ISSN:00219258
DOI:10.1074/jbc.M111.256909