FIG. 4.

Exogenous expression of GATA-1 in FDCW2ER-pXG1 cells activates endogenous GATA-1 gene expression. (A) GATA-1 transcript expression in FDCW2ER-pMG1 and FDCW2ER-pXG1 cells. Expression of GATA-1 in FDCW2ER-pMG1, FDCW2ER-pXG1, and control FDCW2 and FDCW2ER cell lines was assayed initially by Northern blotting of total RNA. As a positive control, RNA from erythroleukemic SKT6 cells was coanalyzed. Equivalence in loading was confirmed by hybridization to a GAPDH probe. (B) Levels of GATA-1 protein expression in FDCW2ER-pCG1, FDCW2ER-pMG1, and FDCW2ER-pXG1 cells. In each of these lines, GATA-1 protein expression levels were assayed by Western blotting of total cell lysates. As negative controls, lysates from FDCW2 and FDCW2ER cells were used while erythroleukemic SKT6 cells served as a positive control. Molecular weight markers (in thousands) are shown in the left margin.