Fig. 5.

Runx1 directly regulates Pu.1 and terminal differentiation through the URE. (A) ChIPseq data for Runx1 in MEL cells from ref. 39. ChIPseq data for Pu.1 in MEL cells were obtained from our previous study (7). (B) K562 cells were electroporated with plasmid vectors encoding dCas9–Cherry and either BFP and a scrambled gRNA or BFP and a gRNA targeting Runx1-binding motifs within the URE. After 48 h, 10,000 BFP⁺Cherry⁺ cells were isolated by FACS, and Pu.1 mRNA levels were measured by RT-qPCR. (C and D) BFUe were isolated from wild-type and URE^−/− mice. The cells were infected with recombinant lentiviruses expressing GFP Runx1 or hPu.1 or a control (empty) vector. After 72 h of culture, GFP+ cells were isolated by FACS, and cells were further incubated in “proliferation medium.” Cell counts were performed at the indicated times by FACS analysis. Statistically significant; **P < 0.01.