TY - JOUR
T1 - Nonconventional glucagon and GLP-1 receptor agonist and antagonist interplay at the GLP-1 receptor revealed in high-throughput FRET assays for cAMP
AU - Chepurny, Oleg G.
AU - Matsoukas, Minos Timotheos
AU - Liapakis, George
AU - Leech, Colin A.
AU - Milliken, Brandon T.
AU - Doyle, Robert P.
AU - Holz, George G.
N1 - Funding Information:
This work was supported by National Institutes of Health Grant R01-DK069575 (to G. G. H.) and by the Holz Laboratory Diabetes Research Fund, dedicated to Mignon M. Holz of the SUNY Upstate Medical University Health Science Center Foundation. Syracuse University holds patent rights on GGP817 conceived of by R. P. D. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Publisher Copyright:
© 2019 Chepurny et al.
PY - 2019/3/8
Y1 - 2019/3/8
N2 - G protein– coupled receptors (GPCRs) for glucagon (GluR) and glucagon-like peptide-1 (GLP-1R) are normally considered to be highly selective for glucagon and GLP-1, respectively. However, glucagon secreted from pancreatic -cells may accumulate at high concentrations to exert promiscuous effects at the -cell GLP-1R, as may occur in the volume-restricted microenvironment of the islets of Langerhans. Furthermore, systemic administration of GluR or GLP-1R agonists and antagonists at high doses may lead to off-target effects at other receptors. Here, we used molecular modeling to evaluate data derived from FRET assays that detect cAMP as a read-out for GluR and GLP-1R activation. This analysis established that glucagon is a nonconventional GLP-1R agonist, an effect inhibited by the GLP-1R orthosteric antagonist exendin(9 –39) (Ex(9 –39)). The GluR allosteric inhibitors LY2409021 and MK 0893 antagonized glucagon and GLP-1 action at the GLP-1R, whereas des-His1-[Glu9]glucagon antagonized glucagon action at the GluR, while having minimal inhibitory action versus glucagon or GLP-1 at the GLP-1R. When testing Ex(9 –39) in combination with des-His1-[Glu9]glucagon in INS-1 832/13 cells, we validated a dual agonist action of glucagon at the GluR and GLP-1R. Hybrid peptide GGP817 containing glucagon fused to a fragment of peptide YY (PYY) acted as a triagonist at the GluR, GLP-1R, and neuropeptide Y2 receptor (NPY2R). Collectively, these findings provide a new triagonist strategy with which to target the GluR, GLP-1R, and NPY2R. They also provide an impetus to reevaluate prior studies in which GluR and GLP-1R agonists and antagonists were assumed not to exert promiscuous actions at other GPCRs.
AB - G protein– coupled receptors (GPCRs) for glucagon (GluR) and glucagon-like peptide-1 (GLP-1R) are normally considered to be highly selective for glucagon and GLP-1, respectively. However, glucagon secreted from pancreatic -cells may accumulate at high concentrations to exert promiscuous effects at the -cell GLP-1R, as may occur in the volume-restricted microenvironment of the islets of Langerhans. Furthermore, systemic administration of GluR or GLP-1R agonists and antagonists at high doses may lead to off-target effects at other receptors. Here, we used molecular modeling to evaluate data derived from FRET assays that detect cAMP as a read-out for GluR and GLP-1R activation. This analysis established that glucagon is a nonconventional GLP-1R agonist, an effect inhibited by the GLP-1R orthosteric antagonist exendin(9 –39) (Ex(9 –39)). The GluR allosteric inhibitors LY2409021 and MK 0893 antagonized glucagon and GLP-1 action at the GLP-1R, whereas des-His1-[Glu9]glucagon antagonized glucagon action at the GluR, while having minimal inhibitory action versus glucagon or GLP-1 at the GLP-1R. When testing Ex(9 –39) in combination with des-His1-[Glu9]glucagon in INS-1 832/13 cells, we validated a dual agonist action of glucagon at the GluR and GLP-1R. Hybrid peptide GGP817 containing glucagon fused to a fragment of peptide YY (PYY) acted as a triagonist at the GluR, GLP-1R, and neuropeptide Y2 receptor (NPY2R). Collectively, these findings provide a new triagonist strategy with which to target the GluR, GLP-1R, and NPY2R. They also provide an impetus to reevaluate prior studies in which GluR and GLP-1R agonists and antagonists were assumed not to exert promiscuous actions at other GPCRs.
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U2 - 10.1074/jbc.RA118.005682
DO - 10.1074/jbc.RA118.005682
M3 - Article
C2 - 30622136
AN - SCOPUS:85062615911
SN - 0021-9258
VL - 294
SP - 3514
EP - 3531
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 10
ER -