Fig. 2: ZIP13 deficiency stopped iron trafficking from the cytosol to Golgi.

a Levels of iron in Golgi. Iron stained by FeRhonox^TM-1(magenta), and Golgi marked by P58-GFP (green). Scale bar, 20 μm. b Levels of cytosolic LIP and Golgi iron measured in WT and Zip13-KO MEFs (Cytosolic LIP and Golgi iron: n = 3). c Protein levels of TfR1, FPN1, FtH, and FtL in WT and Zip13-KO MEFs. d The protein levels of TfR1, hZIP13-MYC, FtH, and FtL. e, f The levels of cytosolic LIP (e) and Golgi iron (f) in Zip13-KO MEFs after hZIP13 expression (n = 3). g, h Golgi iron of WT and Zip13-KO MEFs after treatment with 50 μM FeCl₂ for 24 h (g, n = 3). Scale bar, 50 μm. i A time course of iron transport from the cytosol to Golgi by WT and Zip13-KO MEFs (n = 3). WT and Zip13-KO MEFs were treated with 50 μM FeCl₂ for 0, 0.5, 1, 1.5, and 2 h, respectively, and then collected to detect the Golgi iron contents. j Protein levels of TfR1, FtH, and FtL in WT and Zip13-KO MEFs after with or without FeCl₂ treatment. k GST-N-mZIP13 and GST alone were tested for their abilities to bind Fe²⁺. A Fe²⁺-column (Fe²⁺ replacing Ni⁺) was used. Elution was used to detect whether the protein could bind to Fe²⁺ by Commassie brilliant blue staining (left gel and middle gel) and western blotting (right gel). GST: GST protein, GST-N-mZIP13: fusion protein of mouse ZIP13 N-terminal and GST, E1-E6: eluates collected after passage through ferrous column. l Levels of iron ions were detected in the protein-free control and hZIP13-loaded liposomes at 0 h, 2 h, and 6 h, respectively, to verify the iron-transport activity of ZIP13 (n = 3). Iron levels were represented by relative changes of fluorescence signal (Calcein-Fe²⁺). The “n” represents biologically independent replicates (b, e–g, i, and l). Each experiment was repeated independently at least three times with similar results (c, d, j, and k). Data are mean ± SD. Statistical analysis was performed using two-tailed student’s t-test (b, e–g, and l). Source data are provided as a Source Data file.