GPCR Activation is Measured Using Cisbio’s cAMP and IP1 HTRF® HTplexTM Cell-based Assay

Cisbio, BMG Labtech

GPCRs carry information within cells via two major signaling pathways: regulation of cAMP levels and increases in intracellular Ca2+ triggered by inositol 1, 4, 5- triphosphate (IP3). These signaling pathways are activated by the specific G protein associated with the receptor1 . Activation of a Gs or Gi coupled receptor results in the increase or decrease of cAMP levels, respectively. While activation of a Gq coupled receptor activates phospholipase C (PLC) and triggers the inositol phosphate (IP) cascade. Cisbio Bioassays has developed assay kits capable of monitoring the activation of Gs, Gi and Gq coupled receptors, using their new generation Lumi4-Tb™ TR-FRET Cryptate. This chemistry allows for the detection of two events in one well using two different acceptors, a green dye (λ = 520 nm) and a red dye (λ = 665 nm). This same chemistry is used in Cisbio’s Tag-lite® technology. IP-One and cAMP experiments were performed on the PHERAstar Plus HTS microplate reader using Simultaneous Dual Emission detection.

HTRF microplate readers, GPCR research from A to Z