Functional characterization of cis-acting elements mediating flavone-inducible expression of CYP321A1

► Eight cis elements that regulate CYP321A1 expression are localized. The essential element XRE-Fla that regulates CYP321A1 expression is characterized. XRE-Fla forms two DNA-protein complexes with H. zea fatbody cell nuclear extracts. Flavone increases the nuclear concentration of the trans-factors binding to XRE-Fla. CncC is a candidate trans-factor mediating flavone induction of CYP321A1.