Investigating Potential 5' UTR G-Quadruplexes Within NRF2 mRNA

Post-transcriptional regulation of gene expression is influenced by RNA-binding proteins (RBPs) and small non-coding RNAs that bind to conserved mRNA sequences to modulate mRNA processing. These regulatory molecules affect the structural conformation of mRNAs, creating formations like G-quadruplexes (G4s), which alter translation initiation and regulatory-factor site accessibility. Recent studies have highlighted Nuclear factor erythroid 2-related factor 2 (NRF2) as a key regulator of cellular redox homeostasis and cellular response to oxidative stress. An intriguing feature of NRF2 is the structural formation of its 5' untranslated region (UTR), which may promote or inhibit translation initiation depending on the cellular context. In this study with minigenes, we provide in vitro evidence of RNA G4s in the NRF2 mRNA's 5' UTR under basal (no stress) conditions. Achieved via electrophoretic mobility shift assay and fluorescence spectra in the presence of Pyridostatin. Understanding how structural motifs within NRF2 5' UTRs influence mRNA function provides insights into a common molecular mechanism underlying diseases where NRF2 is dysregulated, like cancers, cardiovascular disease, and neurodegeneration, and highlights potential therapeutic avenues through regulation of NRF2.