NAD Protein ADP Ribosyltransferase is an enzyme that plays a crucial role in post-translational modifications of proteins. It catalyzes the transfer of ADP-ribose from NAD (nicotinamide adenine dinucleotide) to target proteins, a process called ADP-ribosylation. This enzyme is involved in various physiological and cellular processes, including DNA repair, transcription regulation, signal transduction, and cell death.
ADP-ribosylation is a reversible modification that influences protein activity, stability, and protein-protein interactions. NAD Protein ADP Ribosyltransferase transfers the ADP-ribose moiety from NAD to specific amino acid residues, predominantly arginine, but also cysteine and asparagine. This covalent modification can alter the function of the modified protein by affecting its structure, enzymatic activity, or subcellular localization.
The NAD Protein ADP Ribosyltransferase enzyme has been identified in various organisms, including bacteria, plants, and animals, and different isoforms exist within these organisms. Some isoforms are secreted from cells and function as extracellular ADP-ribosylating enzymes, while others remain intracellular.
In summary, NAD Protein ADP Ribosyltransferase is an enzyme that catalyzes the transfer of ADP-ribose from NAD to target proteins, leading to ADP-ribosylation. This post-translational modification can have significant effects on protein function and cellular processes, making this enzyme crucial for a wide range of biological functions.
