Characterization of TERRA 9 repeat G4-binding RHAU peptides by Fluorescence Resonance Energy Transfer

Abstract

Introduction: TERRA (telomeric repeat-containing RNA) is a G-quadruplex (G4) noncoding RNA that plays a part in cancer and aging. Here, we report the use of a fluorescence resonance energy transfer (FRET) approach to explore the binding mode of TERRA 9 repeat G4-binding RHAU peptides. Methods: RHAU peptide was genetically incorporated with the fluorescent protein CFP/YFP, resulting in the generation of the fluorescent protein FRET and RHAU55-CFP/RHAU55-YFP. Results: A strong hetero-FRET was observed when TERRA 9 repeats were added to the RHAU55-CFP/RHAU55-YFP mixture, indicating that TERRA 9 repeats could form G4 structures and simultaneously bind multiple proteins fused with the RHAU peptide. Conclusion: This provides a useful approach for regulating the telomere elongation process by a complex of TERRA and functional proteins fused with the RHAU peptide.