Acetylation
Acetylation is an important modification of proteins in cell biology. N-acetylation, or the transfer of an acetyl group to nitrogen, occurs in almost all eukaryotic proteins through both irreversible and reversible mechanisms. N-terminal acetylation requires the cleavage of the N-terminal methionine by methionine aminopeptidase (MAP) before replacing the amino acid with an acetyl group from acetyl-CoA by N-acetyltransferase (NAT) enzymes. It occurs as a co-translational and post-translational modification of proteins, for example, histones, STAT, and microtubules. Acetylation modification regulates protein conformation, and dysfunction of this modification has been implied in many diseases, including cancer. This type of acetylation is co-translational, in that N-terminus is acetylated on growing polypeptide chains that are still attached to the ribosome. While 80-90% of eukaryotic proteins are acetylated in this manner, the exact biological significance is still unclear.
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