Runx1^R188Q/+ mice express similar levels of Runx1^R188 and Runx1^Q188 in hematopoietic cells. (A) Schematic representation of RUNX1 protein indicating human (hs) and mouse (mm) amino acids and the R188Q mutation. The RUNT homology domain (RHD), nuclear localization signal (NLS), transactivation domain (TAD), and the inhibitory domain (ID) are shown. (B.) Sanger sequencing of region surrounding the edited site in exon 4 from WT and Runx1^R188Q/+ tail DNA, and respective amino acid sequences. (C) Quantification of Runx1^R188 (blue) and Runx1^Q188 (red) transcript isoform levels (relative ratio) from Runx1^R188Q/+ BM cells as estimated by Illumina sequencing. (D) Quantification of Runx1 protein levels in lysates from Runx1^R188Q/+ BM cells, as estimated by western blot densitometric analysis. (E) Spectra analysis (left) and quantification (right) of Runx1 protein isoform levels from Runx1^R188Q/+ BM cells, as estimated by Bead Assisted Mass Spectrometry (BAMS). ns, not significant.