β globin

Cells were lysed in 1X RIPA buffer (Thermo Scientific) supplemented with 1:100 protease inhibitor cocktail (Sigma Aldrich) on ice, and then centrifuged at maximum speed. Supernatants were mixed 1:1 with 2X Laemmli sample buffer (BioRad) under reducing conditions and boiled for 5 min. Following this, samples were separated via sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) for 1.5 hour at 110V, and transferred to nitrocellulose membranes for 1 hr at 90V. Membranes were blocked with 4% (wt/vol) milk 1% (wt/vol) BSA 1X Phosphate Buffer Saline 0.1% (vol/vol) Tween20 (PBS-T), and incubated with the following primary antibodies overnight at 4°C: BCL11-A (Abcam, MA), IKAROS (Santa Cruz Biotechnologies, CA), (Abcam, MA), and α-globin (Santa Cruz Biotechnologies, CA), β- globin (Santa Cruz Biotechnologies, CA), γ-globin (Santa Cruz Biotechnologies, CA), and GAPDH (Millipore, Germany). Membranes were washed 3 times with PBST and incubated with horseradish peroxidase (HRP)-conjugated secondary antibodies for 1h at room temperature (RT). Bands were detected using enhanced chemiluminescence (ECL) (Thermo Scientific). All western blots presented in the manuscript are representative of multiple experiments, as detailed in the figure legend section. Quantifications were obtained with ImageJ software.

Antibodies 3F4 and 8H4 specific for human and both human and mouse PrP^C, respectively, were obtained from Signet Laboratories (Dedham, MA), and Abcam (cat #ab61409, Boston, MA). Antibodies specific to ferritin and β-actin were obtained from Sigma (cat# F5012, Sigma-Aldrich, St. Louis, MO) and Millipore (cat# MAB1501, Bedford, MA) respectively. Antibody to α-globin was from Abcam (cat# ab102758, Boston, MA), and for β-globin, neuroglobin, and glycophorin-A from Santa Cruz Biotechnology Inc. (cat# sc21757, sc30144, and sc19453, Dallas, Texas). Antibody specific for Tf was from GeneTex (cat# GTX21223, Irvine, CA) and for TfR from Millipore (cat# CBL47, Bedford, MA). Hemin (cat# 51280), protoporphyrin IX (cat# P8293) and FAC (cat# F5879) were purchased from Sigma (Sigma-Aldrich, St. Louis, MO). Cell culture supplies were from GIBCO (Life Technologies). All other chemicals were purchased from Sigma Aldrich (St. Louis, MO).