SRA

In mice lacking the heme exporter, FLVCR, differentiation fails at the CFU-E/proerythroblast stage from excessive heme and reactive oxygen species. We show that Flvcr1-deleted CFU-E/proerythroblasts have low GATA1 mRNA and GATA1-target gene mRNAs along with increased ribosomal protein mRNAs as a direct result of increased heme. Thus heme increases ribosomal protein transcription when globin production needs to be increased, and when heme is excessive, GATA1 is reduced allowing for normal termination of erythroid differentiation. This demonstrates that heme and GATA1 are co-master regulators of erythroid differentiation. Overall design: Total RNA obtained from erythroid cells of mice with Flvcr deleted compared to those of wild-type mice and wild-type mice treated with EPO.