Kinases that phosphorylate protein tyrosine residues. These kinases play major roles in mitogenic signalling and can be divided into two subfamilies: receptor tyrosine kinases, that have an extracellular ligand binding domain, a single transmembrane domain and an intracellular tyrosine kinase domain and nonreceptor tyrosine kinases, which are soluble, cytoplasmic kinases.
(18 Nov 1997)