Fig. 1
An in vitro cell line model to study human CDA type IV. a Alignment of human and mouse KLF1 demonstrating the sequence conservation within the C2H2 zinc finger domains. Mutations associated with CDA IV (E325K) and Nan (E339D) are indicated by boxes. Bold amino acids indicate residues which contact DNA when bound. b Western blot of nuclear extracts from cell lines generated in this study. The blot shows presence of KLF1-ER in the nucleus after induction with 4-OHT (+) in a K1-ER cell line and 3 independent clones of the K1-E339K-ER cell line. Full-length blot image is presented in Additional file 1: Figure S1. c Cell pellets from K1 (parental), K1-ER (wild type), and K1-E339K-ER (CDA mutation) lines treated with 4-OHT or ethanol (vehicle control) for 48 h. The redness of the pellet indicates production of hemoglobin. d Cell number and viability measured at 12-h intervals following induction with 4-OHT for K1 (yellow), K1-ER (green), and K1-E339K-ER (purple) cells. Solid line represents number of live cells in culture and dashed line represents the percentage of live cells in culture. Error bars show ± SEM from three independent clones or three biological replicates for parental K1 cells.e Percentage of DAF positive cells (indicating presence of hemoglobin) at 48 h post-treatment with 4-OHT or ethanol. Data are represented as mean ± SEM from 3 clonally independent cell lines. ***P < 0.001 (Student’s t-test)