GSE59859
Control of developmentally primed erythroid genes by combinatorial corepressor actions
How transcription factors (TFs) cooperate within large protein complexes to allow rapid modulation of gene expression during development is still largely unknown. Here we show that the key haematopoietic LIM-domain-binding protein-1 (LDB1) TF complex contains several activator and repressor components that together maintain an erythroid-specific gene expression programme primed for rapid activation until differentiation is induced. A combination of proteomics, functional genomics and in vivo studies presented here identifies known and novel co-repressors, most notably the ETO2 and IRF2BP2 proteins, involved in maintaining this primed state. The ETO2–IRF2BP2 axis, interacting with the NCOR1/SMRT co-repressor complex, suppresses the expression of the vast majority of archetypical erythroid genes and pathways until its decommissioning at the onset of terminal erythroid differentiation. Our experiments demonstrate that multimeric regulatory complexes feature a dynamic interplay between activating and repressing components that determines lineage-specific gene expression and cellular differentiation. Overall design: ChIP-Sequencing profiles of the IRF2BP2, GFI1B and LSD1 proteins were generated using mouse erythroleukemia (MEL) cells. RNA-seq experiments of Irf2bp2-WT, Irf2bp2-KD, Eto2-WT, Eto2-KD, Gfi1b-WT, Gfi1b-KD, Lsd1-WT, Lsd1-KD, MEL-non-induced, and MEL-induced stages were performed using standard RNA-seq protocol. Illumina HiSeq 2000 (standard TruSeq RNA sequencing protocol) was used for the sequencing.