Figure 1. Identification of ETO2-binding partners in erythroid progenitor cells.

(a) Schematic of the ETO2 protein, its 4 Nervy homology regions (NHR1-4) and the C-terminal V5-Bio tag (top). Fusion protein expression and proper tag function in MEL cells were validated by WB analysis. MEL cells expressing only the BirA enzyme were used as a control. (b) Efficient streptavidin IP of ETO2-V5-Bio in MEL cells. Interaction of ETO2-V5-Bio with LDB1 (a known binding partner) was used for validation. (c) ETO2-V5-Bio-interacting proteins identified by LC–MS/MS in MEL cells. Only proteins pulled down in two independent experiments and with low background scores are shown. (d) Co-IP validations of selected ETO2-V5-Bio-interacting proteins in MEL cells using an endogenous ETO2 antibody. Species-matched IgG was used to control for aspecific binding. Full-size images of all western blots shown can be found in Supplementary Fig. 10. Strept-HRP, streptavidin-HRP; Sup, supernatant; endog., endogenous; WB, western blot; IP, immunoprecipitation.