Figure 5.

USF1 is identified as a major trans-acting factor involved in the ERK5-mediated regulation of FAK gene transcription. (A–C) Transcription activity of the mutations of FAK promoter from dual-luciferase assay with deletion of different NFκB binding sites (A), PEA3, Pax3, or GATA1 binding sites (B), or different USF binding sites (C). (D) Transcription activity of the FAK promoter of XJ mutant. (E) The expression level of FAK in USF1-overexpression B16F1 cells. (F and G) The expression levels of USF1, p-USF1, ERK5, and p-ERK5 in B16F1 cells (F) or A549 cells (G) transfected with MEK5D + ERK5, MEK5A + DN-ERK5, or control vector PRK5. (H) ChIP-qPCR assays were performed to determine the binding of USF1 to FAK promoter regions in B16F1 cells transfected with MEK5D + ERK5, MEK5A + DN-ERK5, or control vector PRK5. (I) The expression level of USF1 in two pair of cell lines with different metastatic potentials, B16F10 and B16F1, 95D and 95C, as detected by WB analysis. Data are represented as mean ± SD, *P < 0.05