Figure 1Backsplicing Generates Circular RNAs that Can Be Translated
A pre-mRNA can be spliced to generate a linear mRNA or a circular RNA. When the pre-mRNA splice sites (ss) are joined in the canonical order (top), a linear mRNA is generated that is subsequently translated to produce the annotated full-length protein. Alternatively, backsplicing (bottom) can generate a circular RNA whose ends are covalently joined at the backspliced junction (purple). Translation can initiate at the AUG and elongate past the backspliced junction until a stop codon is reached. This results in the generation of a truncated protein that has a unique C terminus that is not present in the protein generated from the linear mRNA.