(A) (see page 1690) Subcellular localization of full-length or mutant AML1/ETO(MTG8) and AML1/Evi-1. A total of 3 × 10⁴ COS-7 cells were transfected with 4 μg of each construct as indicated and analyzed by immunofluorescence labeling with anti-AML1 serum. Original magnification × 600. (B) The staining pattern of the cells overexpressing AML1 (upper panel), AML1/ETO(MTG8) (middle panel), or AML1/Evi-1 (lower panel) in lower magnification (× 100). (C) Identification of full-length or mutant AML1/ETO(MTG8) and AML1/Evi-1 in cytoplasmic (lanes C) and nuclear (lanes N) fractions of COS-7 cells. COS-7 cells were transfected with the same amount of each construct as indicated in (A), lysed, fractionated, and subjected to SDS-PAGE and immunoblotting using anti-AML1 serum. Each protein was expressed at the anticipated size, as marked by the arrowhead. The cell lysate of untransfected COS-7 cells was also analyzed as a control (mock). Western blotting of the actin and Rb proteins are shown as known cytoplasmic and nuclear proteins, respectively. Molecular weight standards (in kilodaltons) are indicated.