Kinase Family Src

Kinase Classification: Group TK: Family Src

Src kinases are major signaling hubs in animals, transducing signals from receptor tyrosine kinases and other receptors to downstream signaling pathways.

The Src family has the following subfamilies:

Evolution

Src kinases are found in all animals and a few related lineages (choanoflagellates and filastereans). This is the same distribution as the other Src-subgroup families (Csk, Abl, and Tec), suggesting a close functional interaction within this subgroup. The Frk subfamily is found in single copy in many animals, while most other Srcs are in expanded subfamilies that are unique to individual phyla. Most mammalian Srcs fall into three vertebrate-specific Src subfamilies: SrcA, containing FGR, FYN, SRC and YES; SrcB, containing BLK, HCK, LCK, and LYN; and SRM, containing SRM and BRK.

Domain Structure

Srcs have the typical Src subgroup domain structure: SH2-SH3-Kinase with the addition of a myristoylation site on the N-terminus that anchors the protein to the plasma membrane and allows it to signal from the membrane. One choanoflagellate homolog has replaced the myristolyation site by a lipid-binding (and probably analogous) C2 domain [1, 2].

References

1. Manning G, Young SL, Miller WT, and Zhai Y. The protist, Monosiga brevicollis, has a tyrosine kinase signaling network more elaborate and diverse than found in any known metazoan. Proc Natl Acad Sci U S A. 2008 Jul 15;105(28):9674-9. DOI:10.1073/pnas.0801314105 |
2. Li W, Scarlata S, and Miller WT. Evidence for convergent evolution in the signaling properties of a choanoflagellate tyrosine kinase. Biochemistry. 2009 Jun 16;48(23):5180-6. DOI:10.1021/bi9000672 |