Src family kinase

Src family kinase is a family of non-receptor tyrosine kinases that includes nine members: Src, Yes, Fyn, and Fgr, forming the SrcA subfamily, Lck, Hck, Blk, and Lyn in the SrcB subfamily,  and Frk in its own subfamily. Frk has homologs in invertebrates such as flies and worms, and Src homologs exist in organisms as diverse as unicellular choanoflagellates, but the SrcA and SrcB subfamilies are specific to vertebrates.

Src family kinases interact with a variety of cellular cytosolic, nuclear and membrane proteins, modifying these proteins by phosphorylation of tyrosine residues. A number of substrates have been discovered for these enzymes.