title: Label-free optical biosensor for probing integrative role of adenylyl cyclase in G protein-coupled receptor signaling.
abstract: Adenylyl cyclase is considered as an integrator for receptor signaling. However, its integrative role in receptor signaling is largely studied at the level of point of contacts in complex pathways. Here we used forskolin as a pharmacological probe and the resonant waveguide grating (RWG) biosensor to examine the signal integration of G protein-coupled receptors (GPCRs) at the cyclase-cyclic AMP-PKA module. The biosensor is a refractive index sensitive optical biosensor that is capable of detecting ligand-induced dynamic mass redistribution in cells without labels and cellular manipulations. Stimulation of seven cell lines with forskolin led to distinct optical responses, indicative of distinct expressions and/or organization of cyclase isoforms. The forskolin response in A431 was sensitive to the activities of protein kinase A, Rho kinase, and MAP kinases. Desensitization assays showed that the forskolin pretreatment heterologously desensitized G(s) signaling, partially attenuated G(q) signaling, but had complicate impacts on G(i) signaling. This study documents the integrative role of adenylyl cyclase in GPCR signaling and the power of forskolin as a pharmacological probe to differentiate receptor signaling using the label-free biosensor cellular assays.
authors: Biochemical Technologies, Science and Technology Division, Corning Incorporated, Sullivan Park, Corning, New York, USA.
authors: Elizabeth
authors: E
authors: Tran
authors: Ye
authors: Y
authors: Fang
mesh_terms: D000262:Adenylyl Cyclases / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D015374:Biosensing Techniques; D016466:CHO Cells; D002460:Cell Line; D045744:Cell Line, Tumor; D005576:Colforsin / Q000494:pharmacology*; D006224:Cricetinae; D003412:Cricetulus; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D043562:Receptors, G-Protein-Coupled / Q000187:drug effects / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects* / Q000502:physiology; D020032:Tyrphostins / Q000494:pharmacology; D054460:rho-Associated Kinases / Q000187:drug effects / Q000378:metabolism
chemical_list: D047428:Protein Kinase Inhibitors; D043562:Receptors, G-Protein-Coupled; D020032:Tyrphostins; D005576:Colforsin; D000242:Cyclic AMP; D054460:rho-Associated Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D000262:Adenylyl Cyclases