Figure 1.

Structure of both TP63 and major protein isotypes. TP63 uses several transcription initiation sites (arrows) and extensive alternative splicing, to generate a bewildering number of different mRNAs. For clarity, several alternative-splicing routes at the 5′ end of the gene have not been indicated. Several protein domains can be distinguished; of these, the TA domains, the DBD, and the ISO domain are highly homologous to the corresponding domains in p53. The SAM domain and the TID are not contained in the p53 protein. The capacity to transactivate gene expression at a p53-responsive target is given for each of the indicated isotypes.