BAY 2686013

BAY 2686013 is a small molecule antagonist for the human pituitary adenylate cyclase-activating polypeptide receptor (hPAC1-R), a class B G-protein–coupled receptor (GPCR). BAY 2686013 exhibits sub-micromolar target engagement with this receptor, as determined by competition with PACAP1-27 binding to hPAC1-R in HEK293 cells, with cAMP-Time-Resolved Fluorescence Resonance Energy Transfer as the downstream readout. This is suppported by BAY 2686013 mediated inhibition of PACAP1-27 Agonist–Dependent Ca2+ Release, caused by phospholipase C activation and generation of inositol-1,4,5-triphosphate IP3, further downstream signalling events of hPAC1-R agonism, as determined by a Fluorescent Imaging Plate Reader (FLIPR) assay. GPCR selectivity profiling against 25 GPCRs using a FLIPR assay of BAY 2686013 at 10uM demontrated it has antagonistic activity against cannabinoid receptor 1 (−139.6%), histamine receptor H3 (−87.8%) and muscarinic acetylcholine receptor 4 (−111.7%); and agonistic activity against α1A adrenoreceptor (98%), motilin receptor (112%), muscarinic acetylcholine receptor 1 (87%), P2Y2 receptor (86%). Therefore caution should be applied using this probe at concentrations greater than 1uM. It should also be noted that BAY 2686013 does not compete for PACAP1-27 tracer agonist binding in a Tag-lite assay, suggesting it is an allosteric antagonist.