Figure 1. Design of TALE activators targeting the IL-2 promoter.

(A) Illustration of engineered TALE construct. HA, hemagglutinin epitope; NLS, SV40 nuclear localization signal; T₀, recognition of invariant thymine residue; AD, activation domain - VP64 or TATA-box binding protein (TBP). Listed below the construct is the amino acid composition of a typical repeat domain and the RVDs used for DNA recognition. (B) Schematic of the IL-2 promoter (not drawn to scale) and approximate position of each TALE construct relative to the transcriptional start site (TSS). Each TALE is denoted by ‘IL2’ followed by its corresponding alphabet. Enclosed in the dashed-box are TALEs that bind to the TATA-box and their cognate DNA sites are indicated below. All TALEs are fused to VP64 with the exception of TATA-box binding TALEs, which are fused to VP64 (IL2B or IL2D) or TBP (IL2B’ or IL2D’) for comparative analysis. TATA-box is indicated in green. TSS is indicated in red.