Human TGFβ (types I/II) Reporter Assay System

The TGFβ assay uses proprietary human cells that provide constitutive expression of the Human type I and type II Transforming Growth Factor beta Receptors (TGFβ I/II), both of which are transmembrane serine/threonine kinase receptors. Receptor activation results when TGFβ binds to RII, which then phosphorylates and forms a heterodimer complex with Ri. The mechanisms of TGFβ-RI/RII activation and ensuing signal transduction cascade have been well studied and involve the phosphorylation and interplay of a variety of Smad regulatory proteins and transcription factors. Additionally, cross-talk between the activate TGFβ and NF-kB signal transduction pathways have been characterized.

INDIGO’s Reporter Cells include the luciferase reporter gene functionally linked to tandem TGFβ Response Sequences (TRS) derived from hthe human plasminogen activator inhibitor-1 (PAI-1) promoter, a well-characterized TGFβ responsive target gene. The TRS sequences are readily bound by activated dimeric Smad3/Smad4 to initiate formation of a transcription complex. Quantifying changes in luciferase activity in drug-treated cells versus untreated (or vehicle-treated) reporter cells provides a sensitive surrogate measure of drug-induced changes in TGFβ activity.

The principal application of this assay is in the screening of compounds / drug candidates to quantify any functional activity, either agonist or antagonist, that they may exert against the human TGFβ receptor.