Interacting Fech, Mfrn1, and Abcb10 proteins are coordinately induced during MEL cell erythroid differentiation. (A) Endogenous Fech, Mfrn1, and Abcb10 are coinduced in chemically differentiated MEL cells. Mitochondrial lysates collected from MEL cells exposed to 1.5% dimethyl sulfoxide (DMSO) for various lengths of days were serially probed with antisera against Fech (i), antisera against Mfrn1 (ii), antisera against Abcb10 (iii), and antisera against loading control Hsp60 (iv). Endogenous Fech and Mfrn1 proteins are induced (i,ii) and Abcb10 protein is proteolytically processed to a mature isoform in MEL cells during erythroid differentiation (iii). (B) A schematic model for Mfrn1, Abcb10, and Fech forming an oligomeric protein complex, which facilitates the importation of mitochondrial iron for heme biosynthesis in the developing red blood cells.