Post-translational modification
Post-translational modifications (PTMs) are the covalent processes of changing proteins following their synthesis, and release from ribosomes. PTMs are reversible editing events used and carried out in the overall process of post-translational regulation – the control of the levels of active protein; an irreversible event is proteolysis (protein degradation).
Source: Wikipedia — Post-translational modification (CC BY-SA 4.0)