Cell-Based Assays for G-Protein-Coupled/Tyrosine Kinase-Coupled Receptors

Using mammalian cells transiently transfected with receptors, we have developed an assay [Receptor Selection and Amplification Technology (R-SAT); patents pending] that links ligand-dependent cellular transformation to induction of 8-galactosidase in a 96-well plate format. Using these procedures, we have performed high throughput functional assays of receptors that mediate signal transduction by a diversity of mechanisms. Examples include the prostanoid, muscarinic, and neurokinin receptor subtypes that signal via the G-proteins Gq and Gi, the JAK/STAT-linked GM-CSF receptor, the tyrosine kinase neurotrophin receptors, and the classical oncogenes v-ras and p53. The assays have been formatted such that many receptors can be assayed simultaneously (>10 receptors per well) and precise discrimination of ligand efficacy can be obtained (e.g., full and partial agonists, negative and neutral antagonists).