RT Journal Article
SR Electronic
T1 Quantitative single cell analysis of signaling pathways activated immediately downstream of histamine receptor subtypes
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP mol.116.104505
DO 10.1124/mol.116.104505
A1 Jakobus van Unen
A1 Ali Rashidfarrokhi
A1 Eelco Hoogendoorn
A1 Marten Postma
A1 Theodorus W.J. Gadella, Jr.
A1 Joachim Goedhart
YR 2016
UL http://molpharm.aspetjournals.org/content/early/2016/06/28/mol.116.104505.abstract
AB Genetically encoded biosensors based on Forster resonance energy transfer (FRET) can visualize responses of individual cells in real time. Here, we evaluated whether FRET based biosensors provide sufficient contrast and specificity to measure activity of G protein coupled receptors. The four histamine receptor subtypes (H1R, H2R, H3R and H4R) respond to the ligand histamine by activating three canonical heterotrimeric G-protein mediated signaling pathways with a reported high degree of specificity. Using FRET based biosensors we demonstrate that H1R activates Gαq. We also observed that H1R activates Gαi, albeit at a 10-fold lower potency. In addition to increasing cAMP levels, most likely via Gαs, we found that the H2R induces Gαq mediated calcium release. The H3R and H4R activated Gαi with high specificity and a high potency. We demonstrate that a number of FRET sensors provide sufficient contrast to (i) analyze the specificity of the histamine receptor subtypes for different heterotrimeric G-protein families with single cell resolution, (ii) probe for antagonist specificity and (iii) allow the measurement of single cell concentration-response curves.