Fig. 4.

17β-Estradiol promotes time-dependent recruitment of β-actin and actin-interacting proteins to TAP-ERα in MCF-7 cell nuclei. A, TAP-ERα-expressing cells were E₂-deprived (0) and subsequently stimulated for the indicated times (′, minutes), and 1 mg of nuclear proteins was incubated in each case with IgG-Sepharose and, upon binding and extensive washing, directly analyzed by WB, probing the membrane with specific Abs for the indicated proteins. The results shown in the figure were obtained on the same membrane and are representative of replicate experiments. B, cytoplasmic extracts (50 mg) prepared from TAP-ERα-expressing cells stimulated with E₂ for 2 h were prepared as described under “Experimental Procedures” and processed as reported in Fig. 2A. To avoid saturation of the signal, different amounts of samples were loaded in each case as follows: 1:400 for cytosolic extract (lanes 1 and 2), 1:40 for IgG bead slurry (lanes 3 and 4), and 1:25 for each TEV eluate (lanes 5 and 6). *ns, nonspecific band detected by the Abs used.