BioInvenu provides customer compound profiling and library screening using our LinkLight assay cells. BioInvenu also provides customer protein-protein interaction assay development.

In addition, BioInvenu has promoter-reporter assays for services. One example is our PXR/CYP3A4-Luc assay.

Pregnane X receptor (PXR) is a nuclear receptor whose main function is to recognize the presence of foreign toxic substances in the body. The encoded protein of PXR has a ligand-binding domain and a DNA-binding domain and it is a transcriptional regulator of the Cytochrome P450 3A4 (CYP3A4). CYP3A4 is one of the most important oxidizing enzymes involved in the metabolism of organic drugs. The increased expression of CYP3A4 catalyzes the metabolism of up to 90% of drugs.

The PXR/CYP3A4-Luc assay is a HepG2 cell-based assay that assesses luciferase reporter gene expression driven by a human CYP3A4 promoter following activation of PXR. We generated a HepG2 cell line containing a CYP3A4-Luciferase fusion gene. The cells are infected with a PXR BacMam viruses to express the PXR protein. Upon addition of drugs, the PXR receptor is activated, forms a heterodimer with the another nuclear receptor RXR, enters the nucleus, and activates the CYP3A4 promoter which in turn drives luciferase gene expression. The luciferase activity can then be measured on a luminescence plate reader.

The PXR/CYP3A4-Luc assay is validated with a panel of known compounds. The representative data is shown below: