As presented by the ASBMB, small chemical groups are commonly attached to proteins in order to control their activity, localization, and stability. In eukaryotic cells, most proteins are modified at their N-termini by an acetyl group. N-terminal acetylation involves the transfer of an acetyl moiety from acetyl coenzyme A to the α-amino group of the first amino acid residue of a protein and is catalyzed by N-terminal acetyltransferases (NATs). The NATs have been linked to cancer development and most recently a NAT-mutation was found to cause genetic disease.
Now, researchers from the Department of Molecular Biology (MBI), University of Bergen, and Ghent University (VIB) have revealed that a related protein modification, N-terminal propionylation, is conserved among eukaryotes. Interestingly, the NATs were uncovered to also be responsible for this newly discovered modification by transferring a propionyl-moiety from propionyl coenzyme A to various proteins. Thus, the NATs now emerge as multifunctional enzymes with a broad and diverse impact on the eukaryotic proteomes. These results are published in the current issue of Molecular and Cellular Proteomics.
Identification of N-terminal acetyltransferases (NATs) as N-terminal propionyltransferases (NPTs) in yeast and humans. Naa10 (light blue) and other NATs/NPTs catalyze the transfer of an Acetyl (red) moiety or Propionyl (purple) moiety from Ac-CoA (red) or Prop-CoA (purple), respectively, to the N-terminal amino acid residue of a polypeptide. This process may occur both co-translationally while the polypeptide emerges from the ribosome (green) and post-translationally. A major fraction of the eukaryotic proteomes is N-terminally acetylated while a minor fraction is N-terminally propionylated. Arnt Raae, MBI, UiB.
University of Bergen | Department of Molecular Biology