Reactivation of oxidized PTP1B and PTEN by thioredoxin 1

Abstract

The transient inactivation of protein phosphatases contributes to the efficiency and temporal control of kinase-dependent signal transduction. In particular, members of the protein tyrosine phosphatase family are known to undergo reversible oxidation of their active site cysteine. The thiol oxidation step requires activation of co-localized NADPH oxidases and is mediated by locally produced ROS, in particular H2O2. How oxidized phosphatases are returned to the reduced active state is less well studied. Both major thiol reductive systems, the thioredoxin and the glutathione systems, have been implicated in the reactivation of phosphatases. Here, we show that the protein tyrosine phosphatase PTP1B and the dual-specificity phosphatase PTEN are preferentially reactivated by the thioredoxin system. We show that inducible depletion of TRX1 slows down PTEN re-activation in intact living cells. Finally, using a mechanism-based trapping approach we demonstrate direct thiol disulfide exchange between the active sites of thioredoxin and either phosphatase. The application of thioredoxin trapping mutants represents a complementary approach to direct assays of PTP oxidation in elucidating the significance of redox regulation of PTP function in the control of cell signaling.

The cysteine proteome

“…References provide detailed information on interactions of Cys proteins and functional Cys residues illustrated in this figure. TrxR-actin [110]; Trx-dependent regulation of proteins [139]; Ref1-AP1 [258]; TrxR/AP1 [259]; PDGFR [260]; xCT [261]; PTEN-Trx [262, 263]; PTEN-GSH [264]; ASK1-Trx2 [264]; GSTp1-Prx6 [265]; GAPDH-GSH [266, 267]; ND-GSH [268]; p53-Trx [269]; Trx2-Prx3 [270]; Srx-Prx1 and Srx-Prx3 [271, 272]; Grx2-Prx3 [273]; Grx2-Prx3-Trx2 [274]; PDI-UPR sensor [275]; Era-PDI [276]; PDI-TF [277]; Ero-α-PDI and GSH [278]; GPx7-ER [279]; Nrf2 regulatory Cys residues [280]; Srx functional Cys residues [281]. …”

Targeting Thioredoxin System with an Organosulfur Compound, Diallyl Trisulfide (DATS), Attenuates Progression and Metastasis of Triple-Negative Breast Cancer (TNBC)

“…Thioredoxin (Trx) system, mainly consisted of Trx, thioredoxin reductase (TrxR) and nicotinamide adenine dinucleotide phosphate (NAPDH), plays a pivotal role in modulating cellular thiol/disulfide redox status [16,17]. Thioredoxin-1 (Trx-1) as the predominant isoform of Trx is a 12kD ubiquitous protein containing a redox-active disulfide/ dithiol and its cysteine residues are converted to the oxidized intramolecular disulfide bond state (Trx-1-S2) in a reaction [18]. However, the oxidized state can be rapidly restored to reduced state (Trx-1-(SH)2) that is critical to control the protein function with the assistance of TrxR [19].…”

Localized redox relays as a privileged mode of cytoplasmic hydrogen peroxide signaling

“…Its best-studied signaling effects are mediated by the oxidation of thiolates in transcription factors [2], kinases [3,4] and phosphatases [5][6][7][8]. However, whereas the redox active thiolates in these targets react with H 2 O 2 with rate constants in the range of 9−164 M −1 s −1 [5,6,9,1], the cell cytoplasm contains very abundant peroxiredoxins I and II (PrxI, PrxII) [10,11], which react with H 2 O 2 with rate constants in the range of 10 7 -10 8 M −1 s −1 [12,13].…”

“…Here we draw on the present knowledge of the reactivity and cellular concentrations of 2-Cys peroxiredoxins, sulfiredoxin (Srx) and thioredoxin 1 (Trx1) [5,6,12,13,42,9,1] and apply an integrative computational approach to address the four questions raised above.…”