From archaic bacteria to humans, practically all cells can tweak proteins by changing their chemical properties after production. This capability provides ready, adaptive flexibility, enabling cells to react quickly to changing conditions or needs.
2 post-translational modifications – phosphorylation and lysine acetylation – are intracellular communication signals that can have epigenetic effect. Lysine acetylation affects histone employment with a downstream epigenetic effect. Phosphorylation influences expression of protein-building genes by adding a phosphate group. This can alter proteins involved in building other proteins.