Fig. 4

Conservation of proline-rich alternative frames encoding PxxP motifs. a Identification and validation of human frameshift candidates in RNA-seq data. b Schematic illustration of the identification of conserved frameshift-inducing penultimate exons between human and mouse. c Venn diagram showing a significant overlap (hypergeometric test, p < 1.3 × 10⁻²²). d Frequency of SH3-domain-binding proline-rich motifs in human full-length C-termini (black) and frameshift isoforms fulfilling the criteria defined in Fig. 1a (red). e Boxplot comparing the AA content differences between frameshift and full-length frames (gray boxes), and between the sequences 100 AA before (CDS) and after canonical stop codons (UTR, white boxes)