Fig. 1: Exons encoding the N-terminal p63 isoforms, domain architecture as well as oligomeric conformation of p63 isoforms.

a Testis specific GTAp63 is encoded by an upstream exon, named U1, originating from retroviral LTR insertion. mRNA splicing fuses these exons directly to the exon 2, on which the GTA*peptide and the N-terminal part of TAD are located, in this way skipping exon 1. TA*p63 is encoded on exon1. Main splicing events are illustrated by solid lines, less frequently splicing by dotted lines, start codons are indicated by arrows. b Amino acid sequences of the N-terminal p63 isoforms of the corresponding exons, start codons are indicated by arrows. c Domain architecture and oligomeric conformation of p63 isoforms. GTAp63 and TA*p63 possess an N-terminal elongation compared to TAp63, comprising the TA*- or GTA-peptide, respectively, and the common GTA*-peptide, whereas the residual domains are shared by all three isoforms. ΔNp63 possess a truncated transactivation domain. The C-terminal β- and γ-isoforms are created via alternatively splicing. Only the inactive state of TAp63α has a dimeric oligomeric conformation, all other TAp63 and ΔNp63 isoforms show a tetrameric conformation