Boxes show changes that have been observed experimentally and the numbers in these boxes correspond to the following references: 1, Baudenbacher et al. (2008); 2, Schober et al. (2012); 3, Gilda et al. (2016); 4, Miller et al. (2001); 5, JE Gilda & AV Gomes, unpublished data; 6, Bahrudin et al. (2008). PTMs, post‐translational modifications.