The GATA1 N terminus coordinates metabolic reprogramming in erythropoiesis

Mutations in GATA1 that cause skipping of exon 2, which encodes the N terminus, are associated with the myeloid leukemia of Down syndrome and Diamond-Blackfan anemia (DBA). To elucidate the molecular function of this N-terminal region, we used single-cell RNA sequencing (scRNA-seq) on fetal liver cells from Gata1-mutant embryos that express only the short isoform of GATA1 (GATA1s) lacking the N terminus of full-length GATA1 (GATA1FL). scRNA-seq revealed defects in erythropoiesis and aberrant upregulation of glycolytic genes, including PKM, which encodes pyruvate kinase to catalyze the final and irreversible step of glycolysis. Using precision nuclear run-on sequencing and cleavage under targets and release using nuclease (CUT&RUN) after acute GATA1 deletion in erythroid cells, we identified PKM as a direct target of GATA1. Substitution of GATA1FL with GATA1s induced histone lactylation at the PKM promoter, increased pyruvate kinase M (PKM) expression and activity, and enhanced glycolytic flux in erythroid progenitors, without affecting mitochondrial respiration. Importantly, PKM expression is also significantly elevated in patients with DBA with RPS19 mutations, which is associated with reduced levels of GATA1, further supporting a link between GATA1s-driven defective erythropoiesis and dysregulated glycolysis. Together, these findings reveal that GATA1 controls not only heme metabolism but also glycolytic reprogramming.