Simultaneous detection of GPCR second messengers in living cells
Due to their role in signal transmission from the outside to the inside of a cell, G-protein coupled receptors (GPCRs) are prominent drug targets. GPCR-activation leads to changes in second messengers which are commonly measured to identify GPCR-active drugs. Montana Molecular’s biosensors are genetically encoded fluorophores that respond to GPCR-induced changes in cAMP, DAG, PIP2 and Ca2+, hence, indicating GPCR-stimulation in living cells. The sensors are available in red and green versions as well as in versions decreasing and increasing with higher analyte concentrations, perfect for multiplexing purposes. Here we present the use of the biosensors to detect Gi-stimulation without the need for Forskolin or to unambiguously detect Gq activation. The real-time measurements in living cells were done with the CLARIOstar® microplate reader. Its onboard injectors and small measurement intervals enabled to detect fast Ca2+ releases along with changes in DAG.