Tyrosine-protein kinase (PTK) (PTK)

Tyrosine-protein kinases (PTKs) are a large group of enzymes that catalyze the transfer of a phosphate group from ATP to tyrosine residues on specific protein substrates, serving as essential mediators of cellular signaling (UniProt, 2024). They are divided into two main classes: receptor tyrosine kinases (RTKs), which are transmembrane proteins that respond to extracellular ligands, and non-receptor tyrosine kinases (nRTKs), which are located intracellularly and relay signals from various receptors (NIH, 2023). These enzymes play a pivotal role in regulating fundamental cellular processes, including growth, differentiation, adhesion, motility, and survival (PubMed, PMID: 19143330). Aberrant activation of PTKs, resulting from mutations, gene fusions, or overexpression, is a hallmark of many diseases, particularly cancer, where it drives uncontrolled cell proliferation and metastasis (Nature Reviews Drug Discovery, 2021). Consequently, PTKs are among the most important targets for drug development, with a wide array of small-molecule inhibitors and monoclonal antibodies currently used in clinical practice to treat various malignancies and autoimmune disorders (PubChem, 2024; StatPearls, 2023).

Other names

Protein-tyrosine kinaseTyrosine kinaseTPK

Tyrosine-protein kinase inhibitors primarily act by competitively binding to the ATP-binding site of the kinase domain, thereby preventing the phosphorylation of tyrosine residues on substrate proteins. Monoclonal antibodies target the extracellular domain of receptor tyrosine kinases to block ligand binding or prevent receptor dimerization, effectively halting downstream signaling pathways (StatPearls, 2023; PubChem, 2024).