Figure 2. Schematic drawings of the generation of biologically active short peptides. A similar scheme was published by Hashimoto et al. (2008). (A) Hormones and neuropeptides are generated via a large mRNA precursor (blue) in the nucleus, then translated by ribosomes (green) from a single initiation codon and finally processed in the ER and Golgi into small peptides, which are subsequently secreted by vesicles to act far from the production site. (B) Polycistronic smORFs (red) can be translated by several ribosomes (green) along a single mRNA, followed by cell secretion. Peptides from smORFs can also act far from the releasing cell.