Structure and function of SH2-domain containing tyrosine phosphatases.

The importance of tyrosyl phosphorylation in regulating growth factor-receptor-mediated signal transduction is firmly established, but the roles of protein tyrosine phosphatases (PTPases) in these pathways are unclear. PTPases that contain src-homology 2 (SH2) domains, which mediate interactions with specific phosphotyrosyl proteins, probably play an important role in early signaling events following growth factor stimulation. In this review, the two mammalian SH2-containing PTPases, SH-PTP1 and SH-PTP2, are described and their possible roles in signal transduction discussed. In addition, the implications of recent genetic studies in the mouse and Drosophila, which shed light on the actions of these PTPases in physiology and pathology, will be addressed.