Arg216Gln GATA-1, like wild-type GATA-1, binds to FOG-1.

A FLAG-tagged FOG-1 expression construct was cotransfected with various GATA-1 expression constructs into COS cells as indicated. Western blots (top panels) confirm expression from FOG and GATA constructs. (bottom panel) After immunoprecipitation (IP) with anti-FLAG antibody (or anti-myc control antibody), Western blot detection of precipitated GATA-1 shows that Arg216Gln GATA-1 (lane 5), like wild-type GATA-1, binds to FOG-1 (lane 4), whereas Δ200 to 248 GATA-1 (N finger–deleted; lane 6) do not. No immunoprecipitation of GATA-1 is observed in control experiments (remaining lanes).