Succinyllysine is a form of post-translational modification (PTM) involving the attachment of a succinyl group to the lysine residues in proteins. This modification, which is reversible and dynamic, has been identified in both prokaryotic and eukaryotic cells and is involved in the regulation of various cellular and biological processes. Succinyllysine is implicated in altering enzyme activities of metabolic enzymes and controlling protein-protein or protein-nucleic acid interactions, which can have significant effects on cellular functions such as replication, transcription, and are associated with various diseases including cardiovascular diseases and cancer. The modification is suggested to be regulated by enzymes like sirtuins and is responsive to different physiological conditions, indicating its importance in cellular metabolism and disease development.