Bipartite Recognition of DNA by TCF/Pangolin Is Remarkably Flexible and Contributes to Transcriptional Responsiveness and Tissue Specificity of Wingless Signaling
Figure 7
Optimizing motif architecture increases transcriptional output.
(A) Cartoon of the nkdUPE2 W-CRM. A RW4 motif (green box) was altered to an AK6, point mutations indicated in lowercase. (B–D) Brightfield images of 3rd instar imaginal discs stained with X-gal. The “optimized” AK6 containing (OPT) W-CRM (B′, C′, D′) drives higher expression levels of the reporter transgene than the wildtype (WT) W-CRM (B,C,D), and expands the region which responds to Wg signaling (red arrows). Representative wing (B), haltere (C), and eye/antennal (D) imaginal discs shown. (E,F) Confocal images of lacZ immunostained nkdUPE2 W-CRM reporters at embryonic stage 12 (E, E′) and stage 13 (F, F′). The “optimized” reporter has a dramatic increase in expression.