Skip to main content
Figure 5 | Breast Cancer Research

Figure 5

From: Endoplasmic reticulum stress induces PRNP prion protein gene expression in breast cancer

Figure 5

Identification of ER stress response elements (ERSE) in the PRNP promoter. (A) Schematic diagram of two ERSE (ERSEa and ERSEb), one ERSE-like, and one ERSE-II in the human PRNP promoter. (B) Luciferase activity in HEK293T cells transfected with pGL2 (empty vector), pGL-214 (vector containing the first 214 nucleotides of human PRNP promoter), or pGL-538 (first 538 nucleotides of human PRNP promoter) and treated six hours with ER stressors. Data are expressed as the mean ± SD of two experiments done in triplicate. * Indicates P ≤0.05 compared to the control (Ctl). (C) Schematic diagram of the PRNP promoter mutants showing the mutated nucleotides in bold. Putative transcription factor binding sites predicted by TRANSFAC and the conserved motif 4 affected by the mutations are shown. (D) Luciferase activity measured in HEK293T cells transfected with wild type PRNP promoter (pGL-538) or ERSE mutants of the PRNP promoter. Data represent the mean ± SEM of three experiments done in triplicate. * Indicates P ≤0.05 compared to wild type. (E) Luciferase activity in HEK293T cells transfected with wild type or ERSE mutant PRNP promoters and treated with DMSO (control) or ER stressors. The fold increase of luciferase activity calculated for each PRNP promoter construct corresponds to the ratio of the RLU in presence of ER stress over the RLU in presence of DMSO (Control). Data represent the mean ± SEM of three independent experiments done in triplicate. * Indicates P ≤0.05 compared to the control (DMSO) and # indicates P ≤0.05 between the mutants and the wild type PRNP promoter. (F) Schematic diagram showing conservation of human ERSE-like, ERSEa, ERSE-II and ERSEb. Nucleotide sequence alignment of PRNP promoters is from a previous study [48] and from an alignment done with Ensembl databases. N indicates the number of nucleotide. Compared to human PRNP promoter, * indicates a non-conserved and non-complementary nucleotide while X denotes an absent nucleotide.

Back to article page