Background of the antigen
SHP1 is a member of the non receptor protein tyrosine phosphatase subfamily. The PTP family comprises of at least 37 proteins, characterized by a catalytic phosphatase domain of approximately 240 amino acids, and includes both transmembrane and cytosolic enzymes. PTP1B is cytosolic. The PTPs have high substrate specificity for phosphotyrosyl proteins, at the primary sequence level sharing little similarity with the protein serine phosphatases, protein threonine phosphatases, or the acid and alkaline phosphatases. SHP1 is implicated in the control of tyrosine kinase signalling pathways in cellular proliferation, with a potential role in cancer.