Patent ID: 7238491

Claim:
A method of screening a test compound for its ability to induce cytochrome P-450 3A4 (CYP3A4 gene expression comprising i) contacting said test compound with a protein comprised of a ligand binding domain of human pregnane X receptor (hPXR) having the amino acid sequence 141–434 of SEQ ID NO:14, wherein the protein shares at least 96% amino acid sequence identity with the ligand binding domain of SEQ ID NO:14 and retains the sequence's ligand-binding function, ii) determining whether said test compound selectively binds to the ligand binding domain of said protein; and iii) determining whether a test compound that selectively binds to the ligand binding domain of said protein induces receptor binding to a response element in the CYP3A4 gene promoter and expression of a cytochrome P-450 3A4 monooxygenase enzyme.