Figure 1.

Conservation of stall sites across divergent eukaryotes. (A) Schematic representation of stall site analysis. (B) Number of conserved stall sites in homologous genes in yeast, fruit fly, zebrafish, mouse and human. Some stall sites are common in lower and higher vertebrates, indicating their importance in translation regulation. (C) Ribosome profile on the Xbp1 mRNA (here values for H3 library). The schematic of two isoforms is shown, the unspliced, shorter Xbp1u (solid purple) and spliced, with 3’ extension, Xbp1s (striped purple). The stall site at the 3’end of Xbp1u is indicated. (D) Alignment of C-terminal peptide sequences of Xbp1u from fruit fly, zebrafish, mouse and human. The amino acids in the P-site position where the stalling occurs are indicated in bold. Conserved amino acids are highlighted in yellow, while the ones which are most likely critical for stalling are indicated with triangles. A pink triangle indicates a position where S to A mutation has been demonstrated to increase the translational pausing (50).