Protein Tyrosine Phosphatase

Protein Tyrosine Phosphatase

Protein tyrosine phosphatases (EC 3.1.3.48, PTPs, phosphotyrosine phosphatase, phosphoprotein phosphatase (phosphotyrosine), phosphotyrosine histone phosphatase, protein phosphotyrosine phosphatase, tyrosylprotein phosphatase, phosphotyrosine protein phosphatase, phosphotyrosylprotein phosphatase, tyrosine O-phosphate phosphatase, PPT-phosphatase, PTPase, protein phosphatase, PTP-phosphatase) are a group of enzymes that remove phosphate groups from phosphorylated tyrosine residues on proteins. Protein tyrosine (pTyr) phosphorylation is a common post-translational modification that can create novel recognition motifs for protein interactions and cellular localisation, affect protein stability, and regulate enzyme activity. As a consequence, maintaining an appropriate level of protein tyrosine phosphorylation is essential for many cellular functions. Tyrosine-specific protein phosphatases (PTPase; EC 3.1.3.48) catalyse the removal of a phosphate group attached to a tyrosine residue, using a cysteinyl-phosphate enzyme intermediate. These enzymes are key regulatory components in signal transduction pathways (such as the MAP kinase pathway) and cell cycle control, and are important in the control of cell growth, proliferation, differentiation and transformation.