Tyrosine residue in protein (Tyr)

A tyrosyl residue is the side-chain of the amino acid tyrosine present within a protein. Its phenolic hydroxyl group serves as a critical site for post-translational modifications, primarily phosphorylation (by tyrosine kinases) and sulfation, which regulate protein activity, signal transduction, and interactions. Tyrosyl residues are vital for the function of many proteins, contribute to enzymatic activity and stability, and are involved in key cellular processes including DNA repair, cell signaling, and metabolism. Phosphorylation of tyrosyl residues is fundamental to cellular communication and is implicated in a range of diseases, including cancer, owing to dysregulated kinase activity. "Tyrosyl residues in proteins" refers to a chemical building block rather than a distinct molecular target; targeting strategies are typically indirect, involving the enzymes that modify these residues.

Other names

Tyrosyl residueTyrosine residueTyrY

Phosphorylation and dephosphorylation change protein activity. Drugs acting on upstream enzymes (e.g., inhibitors of tyrosine kinases/phosphatases).