Figure 6.
FGFR1 signaling influences the expression of S-phase kinase-associated protein two (Skp2) but not the release of Cks1. (A): Cells were transfected with vectors coexpressing a constitutively active form of FGFR1 (Fc-FGFR1), wild type (wt) FRS2, and wt Cks1. Blot depicts immunoprecipitation of Fc-R1TK (constitutively active FGFR1) 24 hours after cell synchronization and release into maintenance media alone (CTRL), or supplemented with DMSO vehicle (D) or SU5402 (SU). (B): Western blot analysis of Skp2 expression after cell synchronization and release into DMSO vehicle or SU5402 supplemented media. (C): Hypothesized pathways for FGFR1 control of cell cycle progression in hMSCs. Abbreviations: AKT, protein kinase B; Cks1, cyclin-dependent kinase subunit one; CDK, cyclin dependent kinase; FRS, fibroblast receptor substrate; FGFR1, fibroblast growth factor; ERK, extracellular signal-regulated kinase; PI3K, phosphatidylinositide 3-kinases; Rb, retinoblastoma.