Ullmer, C. and Zoffmann, S. and Bohrmann, B. and Matile, H. and Lindemann, L. and Flor, P. J. and Malherbe, P. (2012) Functional monoclonal antibody acts as a biased agonist by inducing internalization of metabotropic glutamate receptor 7. BRITISH JOURNAL OF PHARMACOLOGY, 167 (7). pp. 1448-1466. ISSN 0007-1188, 1476-5381
Full text not available from this repository. (Request a copy)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.
| Item Type: | Article |
|---|---|
| Uncontrolled 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 |
| Subjects: | 500 Science > 590 Zoological sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Zoologie > Molecular and Cellular Neurobiology (Prof. Dr. Peter J. Flor) |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 04 May 2020 05:49 |
| Last Modified: | 04 May 2020 05:49 |
| URI: | https://pred.uni-regensburg.de/id/eprint/17715 |
Actions (login required)
 |
View Item |
