RAMP2 influences glucagon receptor pharmacology via trafficking and signaling
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Endogenous satiety hormones provide an attractive target for obesity drugs. Glucagon causes weight loss by reducing food intake and increasing energy expenditure. To further understand the cellular mechanisms by which glucagon and related ligands activate the glucagon receptor (GCGR), we investigated the interaction of the GCGR with receptor activity modifying protein (RAMP)2, a member of the family of receptor activity modifying proteins. We used a combination of competition binding experiments, cell surface enzyme-linked immunosorbent assay, functional assays assessing the Gαs and Gαq pathways and β-arrestin recruitment, and small interfering RNA knockdown to examine the effect of RAMP2 on the GCGR. Ligands tested were glucagon; glucagonlike peptide-1 (GLP-1); oxyntomodulin; and analog G(X), a GLP-1/glucagon coagonist developed in-house. Confocal microscopy was used to assess whether RAMP2 affects the subcellular distribution of GCGR. Here we demonstrate that coexpression of RAMP2 and the GCGR results in reduced cell surface expression of the GCGR. This was confirmed by confocal microscopy, which demonstrated that RAMP2 colocalizes with the GCGR and causes significant GCGR cellular redistribution. Furthermore, the presence of RAMP2 influences signaling through the Gαs and Gαq pathways, as well as recruitment of β-arrestin. This work suggests that RAMP2 may modify the agonist activity and trafficking of the GCGR, with potential relevance to production of new peptide analogs with selective agonist activities.
Date Issued
2017-06-06
Date Acceptance
2017-05-08
Citation
Endocrinology, 2017, 158 (8), pp.2680-2693
ISSN
0013-7227
Publisher
Oxford University Press (OUP)
Start Page
2680
End Page
2693
Journal / Book Title
Endocrinology
Volume
158
Issue
8
Copyright Statement
© The Author(s). This article has been published under the terms of the Creative Commons Attribution
License (CC BY;
https://creativecommons.org/licenses/by/4.0/
), which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and
source are credited. Copyright for this article is retained by the author(s).
License (CC BY;
https://creativecommons.org/licenses/by/4.0/
), which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and
source are credited. Copyright for this article is retained by the author(s).
Sponsor
Wellcome Trust
Royal College of Surgeons of England
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000406757000024&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
097880/Z/11/Z
RCS 1 year fellowship
Subjects
Science & Technology
Life Sciences & Biomedicine
Endocrinology & Metabolism
ACTIVITY-MODIFYING PROTEINS
GENE-RELATED PEPTIDE
RAT-LIVER
MEDIATED INTERNALIZATION
AMYLIN RECEPTORS
BETA-ARRESTINS
ADRENOMEDULLIN
SPECIFICITY
ACTIVATION
EXENDIN-3
Publication Status
Published