Functional analysis of the putative PAX3-FKHR response elements upstream of the CPT1A transcription start site (TSS). (A) The putative binding sites (ie, PRO1, PRO2, PRO3 and PRO4) containing a composite PD (GTTC/AT/C) and HD (ATTA) recognition site and the corresponding mutants with the PD site mutated (ie, PRO1m, PRO2m, PRO3m and PRO4m). Nucleotide locations are relative to the TSS. (B) Transcriptional activity of putative PAX3-FKHR binding sites. NIH3T3 cells were transfected as indicated 24 hours prior to luciferase assays. TK is the reporter without any PRO sequence and was used as a negative control. Data were expressed as relative luciferase units (RLUs) by normalizing firefly luciferase activity to Renilla luciferase activity. PF, PAX3-FKHR.