A, A diagram showing the simplified structure of the human
F3 promoter region with an illustration of the TIEG
(transforming growth factor-beta-inducible early gene) binding site. KLF binding
region is shown in bold. B, The bold bases indicate the
conservation of the TIEG binding site among species. C, HASMCs were
infected with Ad-LacZ or Ad-Flag KLF11. Forty-eight hours after infection, the
binding of KLF11 to the F3 promoter was determined by ChIP
assays using an antibody against Flag (n=4/group). D-E, A7r5 cells
were transfected with two different length (D), or wt (wild type)
or del (region deleted) (E) luciferase reporter driven by the
F3 promoter and then infected with Ad-LacZ or Ad-KLF11 (50
MOI). Two days later, the luciferase activity was measured and normalized by
Renilla activity. The results are presented relative to
A7r5 transfected with pF3 (−906/+162) (D)
or wt (E) and infected with Ad-LacZ group set as 1 (n=4/group).
**P<0.01 using two-way ANOVA followed by Bonferroni
test (C, D, E). F, Schematic
summary: KLF11 inhibits F3 transcription by directly binding to
the F3 promoter region.