Figure 5.

FGFR1 regulates the subcellular localization of p21 and p27. (A): Western blot analysis of AKT phosphorylation in hMSCs released from SS into FBS or FGF2 supplemented with DMSO (D), SU, or LY. For FGF-2 release condition, the blot was reprobed for total AKT after probing for phospho-AKT. (B): Cells were transfected with eGFP alone, or eGFP fused to p21 or p27, and the subcellular localization of p21 was determined by fluorescence microscopy after 24 hours. (C): Western blot analysis of p21 phosphorylation (pTHr145) in the cytoplasmic (C) and nuclear (N) fractions of cells cultured in the conditions described in (A) for 24 hours. Lamin B1 is the loading control for the nuclear fraction and a-tubulin for the cytoplasmic fraction. Abbreviations: AKT, protein kinase B; D, DMSO; EGFP, enhanced green fluorescent protein; FBS, fetal bovine serum; FGF, fibroblast growth factor; LY, LY294002; SU, SU5402; SS, serum starvation.