| Item type: | Article | ||||
|---|---|---|---|---|---|
| Journal or Publication Title: | British Journal of Pharmacology | ||||
| Publisher: | WILEY | ||||
| Place of Publication: | HOBOKEN | ||||
| Volume: | 167 | ||||
| Number of Issue or Book Chapter: | 7 | ||||
| Page Range: | pp. 1448-1466 | ||||
| Date: | 2012 | ||||
| Institutions: | Biology, Preclinical Medicine > Institut für Zoologie > Molecular and Cellular Neurobiology (Prof. Dr. Peter J. Flor) | ||||
| Identification Number: |
| ||||
| Keywords: | PROTEIN-COUPLED RECEPTORS; CALMODULIN-BINDING; BETA-ARRESTINS; ACTIVATION MECHANISM; PKC PHOSPHORYLATION; ARRIVE GUIDELINES; HORMONE RECEPTOR; RAT HIPPOCAMPUS; MICE LACKING; IN-VIVO; metabotropic glutamate receptor 7; monoclonal antibody; IgG-mediated receptor internalization; biased agonist; ERK1/2; pertussis toxin insensitive | ||||
| Dewey Decimal Classification: | 500 Science > 590 Zoological sciences | ||||
| Status: | Published | ||||
| Refereed: | Yes, this version has been refereed | ||||
| Created at the University of Regensburg: | Yes | ||||
| Item ID: | 63109 |
Web of ScienceAbstract
BACKGROUND AND PURPOSE The mGlu(7) receptors are strategically located at the site of vesicle fusion where they modulate the release of the main excitatory and inhibitory neurotransmitters. Consequently, they are implicated in the underlying pathophysiology of CNS diseases such as epilepsy and stress-related psychiatric disorders. Here, we characterized a selective, potent and functional ...
Abstract
BACKGROUND AND PURPOSE The mGlu(7) receptors are strategically located at the site of vesicle fusion where they modulate the release of the main excitatory and inhibitory neurotransmitters. Consequently, they are implicated in the underlying pathophysiology of CNS diseases such as epilepsy and stress-related psychiatric disorders. Here, we characterized a selective, potent and functional anti-mGlu(7) monoclonal antibody, MAB1/28, that triggers receptor internalization. EXPERIMENTAL APPROACH MAB1/28's activity was investigated using Western blot and direct immunofluorescence on live cells, in vitro pharmacology by functional cAMP and [S-35]-GTP gamma binding assays, the kinetics of IgG-induced internalization by image analysis, and the activation of the ERK1/2 by elisa. KEY RESULTS mGlu(7)/mGlu(6) chimeric studies located the MAB1/28 binding site at the extracellular amino-terminus of mGlu(7). MAB1/28 potently antagonized both orthosteric and allosteric agonist-induced inhibition of cAMP accumulation. The potency of the antagonistic actions was similar to the potency in triggering receptor internalization. The internalization mechanism occurred via a pertussis toxin-insensitive pathway and did not require G alpha(i) protein activation. MAB1/28 activated ERK1/2 with potency similar to that for receptor internalization. The requirement of a bivalent receptor binding mode for receptor internalizations suggests that MAB1/28 modulates mGlu(7) dimers. CONCLUSIONS AND IMPLICATIONS We obtained evidence for an allosteric-biased agonist activity triggered by MAB1/28, which activates a novel IgG-mediated GPCR internalization pathway that is not utilized by small molecule, orthosteric or allosteric agonists. Thus, MAB1/28 provides an invaluable biological tool for probing mGlu(7) function and selective activation of its intracellular trafficking.
Metadata last modified: 19 Dec 2024 09:33
Altmetric