title: Firefly luciferase gene contains a cryptic promoter.
abstract: A firefly luciferase (FLuc) counts among the most popular reporters of present-day molecular and cellular biology. In this study, we report a cryptic promoter activity in the luc+ gene, which is the most frequently used version of the firefly luciferase. The FLuc coding region displays cryptic promoter activity both in mammalian and yeast cells. In human CCL13 and Huh7 cells, cryptic transcription from the luc+ gene is 10-16 times weaker in comparison to the strong immediate-early cytomegalovirus promoter. Additionally, we discuss a possible impact of the FLuc gene cryptic promoter on experimental results especially in some fields of the RNA-oriented research, for example, in analysis of translation initiation or analysis of miRNA/siRNA function. Specifically, we propose how this newly described cryptic promoter activity within the FLuc gene might contribute to the previous determination of the strength of the cryptic promoter found in the cDNA corresponding to the hepatitis C virus internal ribosome entry site. Our findings should appeal to the researchers to be more careful when designing firefly luciferase-based assays as well as open the possibility of performing some experiments with the hepatitis C virus internal ribosome entry site, which could not be considered until now.
authors.affiliation: Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Vinicna 5, 128 44 Prague, Czech Republic.
authors.forename: Václav
authors.initials: V
authors.lastname: Vopálenský
authors.forename: Tomás
authors.initials: T
authors.lastname: Masek
authors.forename: Ondrej
authors.initials: O
authors.lastname: Horváth
authors.forename: Blanka
authors.initials: B
authors.lastname: Vicenová
authors.forename: Martin
authors.initials: M
authors.lastname: Mokrejs
authors.forename: Martin
authors.initials: M
authors.lastname: Pospísek
mesh_terms: D000818:Animals; D002460:Cell Line; D018076:DNA, Complementary / Q000235:genetics; D005786:Gene Expression Regulation; D016174:Hepacivirus / Q000235:genetics; D006801:Humans; D049409:Luciferases, Firefly / Q000235:genetics*; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic
chemical_list: D018076:DNA, Complementary; D049409:Luciferases, Firefly