title: Different Types of Luciferase Reporters Show Distinct Susceptibility to T3-Evoked Downregulation.
abstract: BACKGROUND
  The firefly luciferase reporter protein is a crucial tool for studies targeting a broad range of biological questions. Importantly, luciferase assays are also widely used to explore mechanisms underlying thyroid hormone dependent regulation of gene expression. However, it was demonstrated that the firefly luciferase reporter is subject to triiodothyronine (T3)-evoked, promoter independent downregulation that is mediated by the thyroid hormone receptor. Since this effect can interfere with readout accuracy, the study aimed to find luciferase reporters that are not susceptible to this phenomenon.
  
  
  METHODS
  Luciferase reporter constructs were generated under the control of a minimal thymidine kinase (TK) promoter and transiently transfected into JEG-3 cells to test their activity upon T3 treatment.
  
  
  RESULTS
  Activity of the TK-(dCpG)Luc encoding a synthetic (dCpG)Luciferase and TK-NanoLuc expressing the NanoLuc reporter was not significantly changed by T3 treatment while the firefly luciferase control was suppressed by ∼2.6-fold. T3 also downregulated the activity of Renilla luciferase by ∼30%.
  
  
  CONCLUSIONS
  Novel types of luciferase reporters, especially the synthetic (dCpG)Luciferase, can be more accurate to study T3-regulated gene expression than the classical firefly luciferase reporter. Renilla luciferase, a popular transfection control of dual luciferase assays, should be used with caution in conditions with T3 treatment.
authors.affiliation: Laboratory of Molecular Cell Metabolism, Department of Endocrine Neurobiology, Institute of Experimental Medicine , Hungarian Academy of Sciences, Budapest, Hungary .
authors.forename: Anna
authors.initials: A
authors.lastname: Kollár
authors.affiliation: Laboratory of Molecular Cell Metabolism, Department of Endocrine Neurobiology, Institute of Experimental Medicine , Hungarian Academy of Sciences, Budapest, Hungary .
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Kvárta-Papp
authors.affiliation: Laboratory of Molecular Cell Metabolism, Department of Endocrine Neurobiology, Institute of Experimental Medicine , Hungarian Academy of Sciences, Budapest, Hungary .
authors.forename: Péter
authors.initials: P
authors.lastname: Egri
authors.affiliation: Laboratory of Molecular Cell Metabolism, Department of Endocrine Neurobiology, Institute of Experimental Medicine , Hungarian Academy of Sciences, Budapest, Hungary .
authors.forename: Balázs
authors.initials: B
authors.lastname: Gereben
mesh_terms: D001483:Base Sequence; D045744:Cell Line, Tumor; D015536:Down-Regulation; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects*; D017930:Genes, Reporter; D006801:Humans; D008156:Luciferases / Q000096:biosynthesis* / Q000235:genetics; D049409:Luciferases, Firefly / Q000096:biosynthesis / Q000235:genetics; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D013937:Thymidine Kinase / Q000235:genetics; D037021:Thyroid Hormone Receptors alpha / Q000819:agonists / Q000235:genetics; D014162:Transfection; D014284:Triiodothyronine / Q000494:pharmacology*
chemical_list: D037021:Thyroid Hormone Receptors alpha; D014284:Triiodothyronine; D008156:Luciferases; D049409:Luciferases, Firefly; D013937:Thymidine Kinase