Figure 3

p21 and p27 are localized primarily to the cytoplasm of NMuMG, MDA-MB-231, HMEC, and HaCaT cells. The cytoplasmic (C) and nuclear (N) subcellular fractions prepared in Fig. 1a were analyzed by immunoblot with antibodies specific for p27 or p21. HIRA served as a marker for the nucleus and Raf was used as a marker for the cytoplasm. Cont., control; T + R, 10 ng/ml TGF-β1 plus 100 nM rapamycin; HMEC, primary human mammary epithelial cells.