Evidence that SH2 domains promote processive phosphorylation by protein-tyrosine kinases.

Non-receptor protein-tyrosine kinases often contain at least one Src homology 2 (SH2) domain, a protein module that binds with high affinity to tyrosine-phosphorylated peptides. Because SH2 domains would be predicted to bind with high affinity to proteins phosphorylated by the kinase, but not to the unphosphorylated substrate, their presence in tyrosine kinases has been puzzling. An important role for the SH2 domain of the Abl tyrosine kinase was suggested by work showing that Abl requires an intact SH2 domain in order to malignantly transform cells, and that replacement of the Abl SH2 domain with heterologous SH2 domains alters the spectrum of proteins phosphorylated detectably by Abl in vivo.

Pubmed ID: 7780740 RIS Download