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Characterizing Modulators of Protease-Activated Receptors with a Calcium Mobilization Assay Using a Plate Reader
Published on: May 24, 2024
Receptor activity modifying proteins (RAMPs) interact with the VPAC2 receptor and CRF1 receptors and modulate their
D Wootten1, H Lindmark, M Kadmiel
1School of Life and Health Sciences, Aston University, Birmingham, UK.
British Journal of Pharmacology
|September 6, 2012
Summary
Receptor activity modifying proteins (RAMPs) interact with VPAC(2) and CRF(1) receptors, modulating G-protein signaling. The CRF(1)-RAMP2 interaction shows physiological relevance in mice, impacting hormone release.
Area of Science:
- G protein-coupled receptor (GPCR) research
- Receptor pharmacology
- Signal transduction pathways
Background:
- Receptor activity modifying proteins (RAMPs) are known to interact with various GPCRs, but the functional consequences remain largely unexplored.
- Understanding these interactions is crucial for elucidating complex cellular signaling networks.
Purpose of the Study:
- To investigate the interactions between RAMPs and three specific GPCRs: GLP-1 receptor, VPAC(2), and CRF(1).
- To determine the functional outcomes of these RAMP-GPCR interactions on receptor expression and signaling pathways.
Main Methods:
- Co-transfection of GPCRs and RAMPs in HEK 293S and CHO-K1 cells.
- Assessment of cell surface expression via ELISA.
- Measurement of agonist-stimulated cAMP production, Ca(2+) mobilization, and GTPγS binding.
- In vivo assessment of CRF-stimulated hormone release in Ramp2(+/-) mice.
Main Results:
- VPAC(2) enhanced cell surface expression of all tested RAMPs; CRF(1) enhanced RAMP2 and its own expression.
- No impact on cAMP production, but altered G-protein coupling in a receptor- and agonist-dependent manner.
- CRF(1)-RAMP2 complex increased intracellular calcium in response to CRF and urocortin 1; Ramp2(+/-) mice showed reduced CRF responsiveness.
Conclusions:
- VPAC(2) and CRF(1) receptors physically interact with RAMPs.
- These interactions modulate G-protein coupling specificity.
- The CRF(1)-RAMP2 interaction appears to have physiological significance, influencing hormone release in vivo.
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