Transcriptionally regulated energy metabolism drives early erythropoiesis (RNA-Seq)

Transcription and metabolism both influence cell function but dedicated transcriptional control of metabolic pathways regulating cell fate has rarely been defined. Zebrafish moonshine mutant embryos defective for the transcription elongation factor tif1? do not make red blood cells. Here, through a chemical suppressor screen we discovered that inhibition of the pyrimidine biosynthesis enzyme DHODH rescues erythroid differentiation in moonshine mutant embryos, which depends on the functional link of DHODH to mitochondrial coenzyme Q activity. In-vivo metabolomics analysis reveals that tif1? loss results in mitochondrial respiration defects that are associated with reduced expression of genes that encode coenzyme Q synthesis enzymes and are directly bound and controlled by TIF1?. Treatment of moonshine embryos with a coenzyme Q analogue rescues their bloodless defect. These results demonstrate energy metabolism is a key output of a lineage transcription factor that drives cell fate decisions in the early blood lineage. Overall design: To analyze the effect of TIF1? knockdown on gene expression, we generated independent human HepG2 clonal cell lines stably transduced with either one of two doxycycline-inducible control shRNAs or one of two TIF1? shRNAs and induced them with 1 µg/ml doxycycline for 48 hours.