Figure 1.

Engineering of Mammalian Bright-Ferritin Reporter Gene System

(A) Plasmid vector diagram for CRISPR-Cas9 gene editing for insertion of the human ferritin transgene at the AAVS1 locus.

(B–D) (B) Schematic of stable cell line generation and assay for intracellular nanoparticle formation. Representative TEM of (C) ferritin nanoparticle subcellular localization and (D) purified electron-dense ferritin nanoparticles (red arrowheads) extracted from ferritin-overexpressing cells supplemented with 0.2 mM MnCl₂ for 24 h.

(E) Cellular manganese content from purified ferritin nanoparticles in wild-type (WT) and ferritin-overexpressing (FrT) cells with or without Mn supplementation.

(F) Relative ferritin protein level normalized to α-tubulin in WT and FrT cells. Mn-incubated WT and FrT cells have different ferritin protein expression levels (∗p < 0.05). Data in subfigures (E) and (F) are represented as mean ± SEM.

See also Figures S1 and S2.