FIGURE 3.

Activation of the Arr19 promoter by GATA-1 transcription factor. A, schematic representation of the 1-kb Arr19 promoter (ARR19-P1) marked with putative GATA-1 and CRE motifs, which were identified using the MatInspector Professional Program. B, HEK 293T cells were transiently transfected with the ARR19-P1 reporter construct along with increasing amounts of GATA-1 or CBP expression plasmid or increasing amounts of CBP with a constant amount of GATA-1 expression plasmid, as indicated. C, MA-10 cells were transiently transfected with the ARR19-P1 reporter construct along with CREB or GATA-1 expression plasmid. After 36 h of transfection, cells were incubated for another 6 h with or without cAMP (300 μm). Values represent the means ± S.E. of at least three independent experiments. D, CBP was precipitated with rabbit anti-CBP serum or, as a control, rabbit nonimmune serum (n.i.) containing equal amounts of total IgG. GATA-1 protein was precipitated with rat anti-GATA-1 monoclonal antibody or an isotype-matched irrelevant control rat monoclonal antibody. The secondary anti-rat IgG antibody used for Western blot analysis recognized the rat IgG2a used for the GATA-1 immunoprecipitation. i.p., antibodies used for immunoprecipitations.