NAA50 Human

N Alpha-Acetyltransferase 50 (NAA50), also known as the NatE catalytic subunit, is a protein-coding gene that plays a crucial role in the acetylation of proteins. This enzyme is part of the N-terminal acetyltransferase (NAT) family, which is responsible for the co-translational modification of proteins by acetylating the N-terminus of nascent polypeptide chains. NAA50 is particularly significant due to its broad substrate specificity and its involvement in various cellular processes.

The NAA50 gene is located on human chromosome 3q13.2 . It encodes a protein that is composed of 169 amino acids with a molecular weight of approximately 19 kDa. The protein is characterized by its ability to acetylate the N-terminus of proteins that retain their initiating methionine . This acetylation process is essential for the stability, localization, and function of many proteins.

NAA50 exhibits both N-alpha-acetyltransferase and N-epsilon-acetyltransferase activities . The enzyme acetylates the initiator methionine of most peptides, except those with a proline in the second position . Additionally, it can acetylate the side chain of specific lysines on proteins, although the relevance of this activity in vivo remains unclear .

The acetylation process mediated by NAA50 is crucial for several cellular functions, including the establishment of mitotic sister chromatid cohesion and the regulation of protein-protein interactions . NAA50 is also involved in the acetylation of histone H4, which plays a role in chromatin remodeling and gene expression .

NAA50 is predominantly localized in the cytosol and nucleus of cells . It is a part of the NatA complex, which is associated with ribosomes where the acetylation reaction occurs co-translationally as the peptide extrudes from the ribosome . This localization is essential for its function in modifying newly synthesized proteins.

Mutations or dysregulation of the NAA50 gene have been associated with several diseases, including Chops Syndrome and Ogden Syndrome . These conditions are characterized by developmental delays, intellectual disabilities, and other systemic abnormalities. Understanding the role of NAA50 in these diseases can provide insights into potential therapeutic targets.

Recombinant human NAA50 is widely used in research to study protein acetylation and its effects on cellular functions. The enzyme’s broad substrate specificity makes it a valuable tool for investigating the mechanisms of protein modification and its implications in health and disease .