Protein Acetylation

Protein post-translational modification (PTM) is a key link in protein expression. Among them, acetylation modification is associated with diseases such as tumors, aging, bacterial infections, and nephropathy, and is involved in biological processes such as DNA damage repair, protein folding, mitochondrial function, metabolism, and drug resistance. Protein acetylation modification involves the process of transferring and adding an acetyl group to a protein lysine residue or protein N-terminus, catalyzed by an acetyltransferase (or non-enzymatic enzyme). This modification can affect protein structure, function, and intracellular interactions. Its dynamic nature and regulatory interplay with deacetylation contribute to intricate cellular mechanisms and overall biological function.

Learn more about Histone Acetyltransferase Pathway

Mechanisms of Protein Acetylation

Acetylation modifications are mainly divided into two categories: acetylation modification at the N-terminus of the protein and acetylation modification on the protein lysine.

Figure 1. Schematic outline of N-terminal and lysine protein acetylation.
(Source: Ree, R. et al., 2018)

N-terminal Acetylation

N-terminal acetylation involves the attachment of an acetyl group to the α-amino group at the N-terminus of proteins. This modification occurs co-translationally, meaning it takes place while the protein is being synthesized on the ribosome. The enzymatic machinery responsible for N-terminal acetylation is a group of enzymes known as N-terminal acetyltransferases (NATs).

NATs catalyze the transfer of the acetyl group from acetyl-coenzyme A (acetyl-CoA) to the N-terminus of nascent polypeptide chains. This process occurs shortly after the initiator methionine residue is cleaved by methionine aminopeptidases. NATs recognize specific sequence motifs or structural features at the N-terminus of proteins, allowing them to selectively acetylate certain proteins.

Lysine Acetylation

Lysine acetylation involves the addition of an acetyl group to the ε-amino group of lysine residues within proteins. This modification can occur co-translationally or post-translationally, meaning it can take place during or after protein synthesis. Lysine acetylation is dynamically regulated by two main classes of enzymes: lysine acetyltransferases (KATs) and lysine deacetylases (KDACs), also known as histone deacetylases (HDACs).

KATs catalyze the transfer of the acetyl group from acetyl-CoA to the lysine residue within the protein. They recognize specific target lysine residues based on sequence motifs or structural features in the protein. KATs exhibit substrate specificity and can acetylate multiple lysine residues within a protein or different proteins altogether.

Conversely, KDACs or HDACs are responsible for the removal of acetyl groups from lysine residues, thereby mediating deacetylation. HDACs can reverse the acetylation process by hydrolyzing the acetyl group from the lysine residue, leading to the restoration of the unmodified state of the protein. The deacetylation activity of HDACs plays a crucial role in regulating the dynamic balance of lysine acetylation in cells.

Analysis of Protein Acetylation

• Traditional protein acetylation detection method
  
  • Immunoassays: Use specific antibodies to recognize acetylated proteins. Western blot and immunohistochemistry are the most commonly used methods.
  • Radioactive detection method: Use radioactively labeled acetyl groups or acetylation substrates to detect acetylation reactions.
  • High-performance liquid chromatography (HPLC): Quantify protein acetylation levels by separating and detecting acetylated amino acids in protein hydrolysates.
• Mass spectrometry-based detection
  Mass spectrometry allows direct detection and identification of acetylation sites in proteins, independent of antibodies, and provides quantitative and localization information.
  
  • Tandem mass spectrometry (MS/MS): Identifies acetylation sites and quantifies protein acetylation levels through selective ion breakage and fragmentation analysis.
  • Analysis of PTMs by mass spectrometry: Through specific modifying enzymes and chemical reactions, acetylation modifications are converted into other detectable modifications, expanding the detection range of protein acetylation.
  • LC-MS/MS: Combining liquid chromatography and mass spectrometry technology to achieve high-throughput identification and quantification of acetylation sites.

Figure 2. Detection of lysine acetylation in sugarcane histone H3 by MS/MS spectrum.
(Source: Moraes, I. et al., 2015)

• High-throughput proteomics technology
  The combination of mass spectrometry and proteomics approaches allows for large-scale protein acetylation analysis, revealing the association of acetylation modifications with disease development.
• Chemical biology approaches
  Using chemical synthesis and genetic engineering, researchers can design novel acetylation probes and sensors to enable real-time monitoring of protein acetylation in living cells.
• Bioinformatics analysis
  Combined with big data analysis and machine learning algorithms, researchers can mine the patterns and functions of acetylation modifications to deepen the understanding of protein acetylation regulatory networks.

For research use only, not for use in diagnostic procedures.

Protein Acetylation Antibodies