Deglutathionylation of 2-Cys Peroxiredoxin Is Specifically Catalyzed by Sulfiredoxin

Abstract

Reversible protein glutathionylation plays a key role in cellular regulation and cell signaling and protects protein thiols from hyperoxidation. Sulfiredoxin (Srx), an enzyme that catalyzes the reduction of Cys-sulfinic acid derivatives of 2-Cys peroxiredoxins (2-Cys Prxs), has been shown to catalyze the deglutathionylation of actin. We show that deglutathionylation of 2-Cys Prx, a family of peroxidases, is specifically catalyzed by Srx. Using the ubiquitously expressed member of 2-Cys Prx, Prx I, we revealed the following.

Regulation by Glutathionylation of Isocitrate Lyase from Chlamydomonas reinhardtii

“…These results suggest that the TRX-mediated increase of ICL activity previously observed in total extracts of C. reinhardtii (10) was probably indirect. This apparent activation could be due to the presence of TRX-reducible GRXs in the extract (40,41) or other enzymes catalyzing deglutathionylation, such as sulfiredoxins (42,43). However, the possibility cannot be completely ruled out that a disulfide bond could be formed in CrICL in vivo under specific conditions or by interaction with partner proteins not present in our in vitro assays.…”

Peroxiredoxin Functions as a Peroxidase and a Regulator and Sensor of Local Peroxides

“…As exemplified by the tyrosine phosphorylation-dependent inactivation of Prx I, the peroxidase function of Prx can be regulated via various post-translational modifications. Such modifications also include threonine and serine phosphorylation (82,83), lysine acetylation (84), cysteine glutathionylation (85,86), cysteine nitrosylation (87), and limited proteolysis (88), although the biological relevance of these reactions remains unclear at the present time. Prxs also interact with numerous proteins, which might direct their cellular localization and sensitivity to oxidation (5).…”

Glutathionylation of the Active Site Cysteines of Peroxiredoxin 2 and Recycling by Glutaredoxin

“…Park et al (25,26), who generated adducts by overnight incubation of reduced Prxs with 10 mM GSSG, focused mainly on glutathionylation of Cys-83 in Prx1 (which is not present in Prx2) and reversal by sulfiredoxin. Others have detected glutathionylated Prxs in proteomic screens and observed secretion from cells under oxidative and inflammatory stress (27,28).…”

“…Glutathionylation of the isolated proteins has been observed but only after extended incubation with nonphysiological GSSG concentrations (25,26), and recycling of Prx1 and Prx2 by GSH and Grx1 was not apparent in initial studies (21). However, glutathione adducts have been detected in cell systems (25,27,28) and could therefore be physiologically relevant. We have characterized the interactions between GSH and Prx2 using mass spectrometry to detect products.…”