Redox regulation of PTEN and protein tyrosine phosphatases in H2O2-mediated cell signaling

Protein tyrosine phosphatase (PTP) is a family of enzymes important for regulating cellular phosphorylation state. The oxidation and consequent inactivation of several PTPs by H2O2 are well demonstrated. It is also shown that recovery of enzymatic activity depends on the availability of cellular reductant;. Among these redox-regulated PTPs, PTEN, Cdc25 and low molecular weight PTP are known to form a disulfide bond between two cysteines, one in the active site and the other nearby, during oxidation by H2O2. The disulfide bond likely confers efficiency in the redox regulation of the PTPs and protects cysteine-sulfenic acid of PTPs from further oxidation. In this review, through a comparative analysis of the oxidation process of Yap1 and PTPs, we propose the mechanism of disulfide bond formation in the PTPs. (C) 2004 Published by Elsevier B.V. on behalf of the Federation of European Biochemical Societies.