title: Utility of an appropriate reporter assay: Heliotrine interferes with GAL4/upstream activation sequence-driven reporter gene systems.
abstract: Reporter gene assays are widely used for the assessment of transcription factor activation following xenobiotic exposure of cells. A critical issue with such assays is the possibility of interference of test compounds with the test system, for example, by direct inhibition of the reporter enzyme. Here we show that the pyrrolizidine alkaloid heliotrine interferes with reporter signals derived from GAL4-based nuclear receptor transactivation assays by a mechanism independent of luciferase enzyme inhibition. These data highlight the necessity to conduct proper control experiments in order to avoid perturbation of reporter assays by test chemicals.
authors.affiliation: Federal Institute for Risk Assessment, 10589 Berlin, Germany; Department of Nutritional Toxicology, Institute of Nutritional Science, University of Potsdam, 14558 Nuthetal, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Luckert
authors.affiliation: Federal Institute for Risk Assessment, 10589 Berlin, Germany. Electronic address: stefanie.hessel@bfr.bund.de.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Hessel
authors.affiliation: Federal Institute for Risk Assessment, 10589 Berlin, Germany.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Lampen
authors.affiliation: Federal Institute for Risk Assessment, 10589 Berlin, Germany.
authors.forename: Albert
authors.initials: A
authors.lastname: Braeuning
mesh_terms: D000818:Animals; D048888:Fireflies; D017930:Genes, Reporter / Q000187:drug effects* / Q000235:genetics; D049409:Luciferases, Firefly / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D049410:Luciferases, Renilla / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D011763:Pyrrolizidine Alkaloids / Q000737:chemistry / Q000494:pharmacology*; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D048790:Renilla
chemical_list: D011763:Pyrrolizidine Alkaloids; D012333:RNA, Messenger; D049410:Luciferases, Renilla; D049409:Luciferases, Firefly; C010178:heliotrine
keywords: Firefly luciferase inhibition; Nuclear receptor; Transactivation assay