Figure 1.

sORFs as source of functional short proteins. Translation of short open reading frames (sORFs) can generate short proteins (light blue sphere) with diverse intracellular and extracellular roles. Functions range from cytoplasmic regulation of enzymes, protein-protein interactions, enzymatic activities to regulation of transcription factors in the nucleus and extracellular roles as signals, membrane-associated proteins or antigens presented on MHC-type molecules.