Gabp activates and binds Gfi-1 promoter and Gfi-1 expression partially rescues Gabpa KO phenotype. (A) Expression from Gfi1 promoter when cotransfected with Gabpa alone, Gabpb alone, or Gabpa and Gabpb together, expressed as normalized relative light units (RLU). *P < .01 by ANOVA. (B) ChIP of indicated regions of mouse Gfi1 gene performed with no input DNA (H2O); input DNA not subjected to ChIP (Input); and ChIP performed with no antibody (no Ab), control IgG, and anti-Gabpα antibody (GABP); ets 1,2,3 and ets 4 correspond to Gfi-1 promoter regions shown in panel C. (C) Transfection into 293 cells of indicated Gfi1 promoter constructs alone, described relative to transcriptional start site; mut refers to mutation of the indicated ets sites (left). Promoter activity expressed as normalized RLU, ± SEM (right). *P < .01 by Student t test. (D) In vitro colony formation per 5 × 104 plated cells ± SEM by Lin− bone marrow cells from control or KO mice, transduced with MSCV empty virus or MSCV–Gfi-1 retrovirus, selected in puromycin, and grown in G-CSF and GM-CSF. *P < .01. (E) Statistical summary of CD11b and Gr1 expression by Lin− control or KO bone marrow cells transduced with control MSCV or MSCV–Gfi-1 virus as shown in supplemental Figure 9. *P < .05 between the corresponding control and KO cells. All findings include data from at least 3 independent biologic specimens.
