Fig. 3: G4 formation in intracellular mitochondria.

a Schematic illustration of mitochondrial targeting gene expression regulated by G4 forming sequence. The images were partially adapted from Chuah et al. ⁴⁹ with permission from ACS. b Images of confocal microscopy of HeLa cells transfected with L, D2, and D4 sequences containing plasmid DNAs. c Relative expression level of GFP of HeLa cells. The signals were normalized with those from the cells infected with L-plasmid DNAs as 100%. The expression levels of nucleus were taken in the previous study⁴⁰. GFP expression in mitochondria by D4 sequences was significantly lower than that by the control sequence, as indicated by two-tailed t-test (p = 0.0352, n = 3 independent experiments). The effect size of the GFP expression in mitochondria and nucleus, measured by Cohen’s d, was 1.35 and 0.80 for D2 and D4 sequences, respectively, indicating that the effect size is large. Thus, we conclude that there is a practical significance between the measurements in nucleus and mitochondria for both sequences.