New Case Study:

High-throughput technologies for Gi GPCR drug discovery

Introduction

G protein–gated inwardly rectifying potassium (GIRK) channels strongly shape neuronal and cardiac excitability and, in the brain, mainly form Kir3.1/Kir3.2 heterotetramers activated by Gβγ released from Gi/o-coupled GPCRs, making GIRK activity a direct, physiological readout of Gi/o signaling. Traditional Gi/o assays such as FRET, BRET, or cAMP measurements are limited by pathway complexity or depend on artificial adenylate cyclase stimulation. Here we present a scalable Gi/o GPCR platform for high-throughput, real-time GIRK quantification using both fluorescence and automated patch clamp. The assay uses HEK293 cells stably expressing Kir3.1/3.2 and allows just-in-time transient expression of diverse Gi/o-coupled GPCRs. GIRK activation by ML297 produced comparable EC50 values across fluorescence and electrophysiology, and receptor-driven responses were absent in control HEK cells lacking M2 or GIRK. Overall, this method enables reproducible pharmacology across many neurotransmitter receptors and supports discovery of modulators of Gi/o-linked GPCRs.

Gi GPCR Assay Platform

Stable cell line over-expressing GiRK channels that enables:

  • Fluorescence and automated electrophysiology-based readouts bridge the gap from hit identification to validation workflows, all at high throughput
  • Transient GPCR expression using plasmids, lentivirus, or bacmam vectors for maximum flexibility and fast turnaround times

This cross-platform screening technology gives reliable results to accelerate your next discoveries.

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