REVERSIBLE OXIDATION OF PROTEIN TYROSINE PHOSPHATASES

摘要

The invention relates to a method of identifying any protein tyrosine phosphatase PTP that undergoes reversible modification of PTP active site invariant cysteine within a cell, such that the phosphatase is transiently protected from irreversible active site invariant cysteine-directed PTP inactivating agents. Methods related to regulation of PTPs by reactive oxygen species ROS in a cellular environment are provided. Multiple PTPs are shown to be reversibly oxidized and inactivated following treatment of cells with HZOZ or with physiological stimuli that promote ROS formation, and inhibition of PTP function is shown to contribute to ROS­induced mitogenesis. Transient oxidation of the PTP catalytic site invariant cysteine is exploited in methods to identify which of multiple candidate PTPs are components of a given biological signal transduction pathway, without a requirement for first specifically purifying any particular candidate PTP.