N-terminal protein amino acid acetylation

Definition

Target type: biologicalprocess

The acetylation of the N-terminal amino acid of proteins. [GOC:ai]

N-terminal protein amino acid acetylation is a ubiquitous post-translational modification (PTM) in eukaryotes, and is also found in some bacteria and archaea. This modification involves the addition of an acetyl group from acetyl-CoA to the α-amino group of the N-terminal residue of a protein. The acetyl group is typically transferred by a family of enzymes called N-terminal acetyltransferases (NATs).

There are multiple NATs, each with varying substrate specificities and cellular localization. The most common NAT is N-terminal acetyltransferase A (NatA), which acetylates proteins with small, uncharged residues such as methionine, alanine, glycine, serine, and threonine at their N-terminus. Other NATs, such as NatB and NatC, acetylate proteins with specific N-terminal sequences.

N-terminal acetylation can occur co-translationally, meaning it happens while the protein is being synthesized by the ribosome, or post-translationally. Co-translational acetylation is typically carried out by NatA, while post-translational acetylation can be catalyzed by different NATs.

This modification plays a crucial role in a variety of cellular processes:

* **Protein stability:** N-terminal acetylation can increase protein stability by protecting the N-terminus from degradation by proteases.
* **Protein folding:** Acetylation can influence the folding and conformation of proteins, thereby impacting their function.
* **Protein-protein interactions:** Acetylation can modulate the interaction of proteins with other proteins, affecting their localization and function.
* **Cellular localization:** The modification can influence the trafficking and localization of proteins within the cell.
* **Regulation of enzymatic activity:** Acetylation can regulate the activity of some enzymes.

In some cases, the presence or absence of N-terminal acetylation can influence the interaction of proteins with other cellular components, such as chaperones, leading to changes in protein fate and function.

The regulation of N-terminal acetylation is complex and involves multiple factors, including the availability of acetyl-CoA, the activity of NATs, and the accessibility of the N-terminal residue. In addition, some proteins are specifically deacetylated by enzymes called N-terminal deacetylases, further highlighting the dynamic nature of this modification.

Overall, N-terminal acetylation is a fundamental PTM that significantly impacts protein fate and function. It plays a vital role in various cellular processes and its dysregulation can contribute to disease development.'
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Proteins (1)

Compounds (2)