What amino acids are primarily involved in SUMOylation?

SUMOylation is a post-translational modification process where Small Ubiquitin-like Modifier (SUMO) proteins are conjugated to target proteins, influencing various cellular functions such as nuclear transport, transcriptional regulation, and DNA repair. The primary amino acid involved in this modification is lysine.

During the SUMOylation process, the carboxyl group of the SUMO protein forms an isopeptide bond with the amino group of the lysine residue in the target protein. This specific interaction is crucial as it allows for the attachment of SUMO to the substrate, ultimately affecting the protein's stability, localization, and function.

Lysine residues are particularly suited for this type of modification due to their positive charge and the availability of their amino group, which facilitates the formation of the isopeptide bond with the SUMO molecule. Therefore, the involvement of lysine in SUMOylation is well established in biochemical studies, underscoring its critical role in the process.