Background of the antigen
The steady state of protein tyrosyl phosphorylation in cells is regulated by the opposing action of tyrosine kinases and protein tyrosine phosphatases (PTPs). Several groups have independently identified a non transmembrane PTP, designated SHPTP1 (also known as PTP1C, HCP and SHP), which is primarily expressed in hematopoietic cells and characterized by the presence of two SH2 domains N terminal to the PTP domain. A second and much more widely expressed PTP with SH2 domains, SHPTP2 (also designated PTP1D and Syp), has been identified. SHP2 is a protein tyrosine phosphatase that is widely expressed and plays a regulatory role in various cell signaling events that are important for many cell functions, such as mitogenic activation, metabolic control, transcription regulation, and cell migration.
