Characterization of Mammalian Sulfiredoxin and Its Reactivation of Hyperoxidized Peroxiredoxin through Reduction of Cysteine Sulfinic Acid in the Active Site to Cysteine

Redox-based regulation of signal transduction: Principles, pitfalls, and promises

“…Repair of the sulfinyl group supports the concept that the Prx inactivation-reactivation cycle represents a cell signaling loop [50,[63][64][65][66] (Table 1). This notion is supported by recent studies that show that cell cycle arrest is associated with recruitment of hyper-oxidized PrxII to high molecular weight oligomers, and that recovery is correlated with regeneration of reduced enzyme [67].…”

The Peroxiredoxin Repair Proteins

“…With this method the decrease in the sulfinic acid form of hPrxI was monitored over time following treatment with the recombinant forms of rat, mouse, and human Srx. All Srx variants exhibited the same specific activity in the presence or absence of an N-terminal GST affinity tag (Chang et al, 2004). Moreover, Srx purified from A549 human lung epithelial cells had the same specific activity.…”

“…Moreover, Srx is not able to repair the sulfinic acid form of GAPDH. It is important to note here that while Srx can repair PrxI-IV in vitro, Srx most likely only repairs PrxI and PrxII since both molecules are localized to the cytosol (Chang et al, 2004). In contrast, PrxIII and PrxIV are located in the mitochondria and the extracellular space, respectively.…”

“…Srx appears to be a ubiquitous protein with large differences in concentration among tissues, suggesting that the level of Srx may be an indicator of the oxidative stress response. A higher abundance of Srx is observed in brain, colon, liver, spleen and spinal cord (Chang et al, 2004). In Arabidopsis both the typical 2-Cys Prx and Srx are located in the chloroplast (Dietz et al, 2006;Liu et al, 2006).…”

“…In these studies three activity assays have been utilized: (i) sulfinic acid reductase activity based on the decrease in the immuno-reactive band to Prx-SO 2/3 -, (ii) ATPase activity corresponding to the increase in the amount of inorganic phosphate released, (iii) binding of Srx to Prx using the Srx-GST fusion and GSH-sepharose Chang et al, 2004;Woo et al, 2005;Jeong et al, 2006). The results from these studies suggest that the initial steps in the reaction may need to be reconsidered and evaluated by further experimentation.…”