Figure 4. Analysis of the inhibition of mutated GLI1 activity by PTCH1.

(A) Effects of PTCH1 on the transcriptional activity of wild-type and mutated forms of GLI1 in HEK-293 cells. Both the Gly¹²² to alanine and His¹²³ to alanine mutated GLI1 constructs, which are resistant to SUFU inhibition, can be inhibited by PTCH1. (B) As in (A), except that the reporter construct was a synthetic enhancer consisting of 12 copies of the GLI-binding consensus site linked to the TK basal promoter and the luciferase reporter gene. The results were similar to those obtained with the PTCH2 promoter.