Prdx1 Interacts with ASK1 upon Exposure to H2O2 and Independently of a Scaffolding Protein

Abstract

Hydrogen peroxide (H2O2) is a key redox signaling molecule that selectively oxidizes cysteines on proteins. It can accomplish this even in the presence of highly efficient and abundant H2O2 scavengers, peroxiredoxins (Prdxs), as it is the Prdxs themselves that transfer oxidative equivalents to specific protein thiols on target proteins via their redox-relay functionality. The first evidence of a mammalian cytosolic Prdx-mediated redox-relay—Prdx1 with the kinase ASK1—was presented a decade ago based on the outcome of a co-immunoprecipitation experiment. A second such redox-relay—Prdx2:STAT3—soon followed, for which further studies provided insights into its specificity, organization, and mechanism. The Prdx1:ASK1 redox-relay, however, has never undergone such a characterization. Here, we combine cellular and in vitro protein–protein interaction methods to investigate the Prdx1:ASK1 interaction more thoroughly. We show that, contrary to the Prdx2:STAT3 redox-relay, Prdx1 interacts with ASK1 at elevated H2O2 concentrations, and that this interaction can happen independently of a scaffolding protein. We also provide evidence of a Prdx2:ASK1 interaction, and demonstrate that it requires a facilitator that, however, is not annexin A2. Our results reveal that cytosolic Prdx redox-relays can be organized in different ways and yet again highlight the differentiated roles of Prdx1 and Prdx2.

How abundant are superoxide and hydrogen peroxide in the vasculature lumen, how far can they reach?

“…Extracellular H 2 O 2 concentrations in the nM scale are still substantially higher than cytosolic ones under physiological conditions [ 68 , 69 ], and therefore cause an influx that can significantly increase cytosolic H 2 O 2 concentrations. At such low influx rates — up to 100's nM s −1 — virtually all H 2 O 2 is captured by cytosolic Prdx1 and Prdx2, which become oxidized and can relay the oxidation to other proteins [ [27] , [28] , [29] , [30] ]. Given the large Prdx reduction capacities of some human cells [ 76 , 77 ], these low H 2 O 2 influx rates may just minimally oxidize the cytosolic Prdx pool.…”

“…Second, it is dismutated via extracellular superoxide dismutase (SOD3). Erythrocytes and ECs absorb the resulting H 2 O 2 [ 21 , 22 ], which readily oxidizes the cytosolic peroxiredoxins (Prdx) 1 and 2 ( k = 0.13-1.6 × 10 8 M −1 s −1 [ [23] , [24] , [25] , [26] ]), eventually driving redox relays that transduce these signals [ [27] , [28] , [29] , [30] ]. Third, it reacts extremely fast with nitric oxide ( • NO) ( k = 1.9 × 10 10 M −1 s −1 [ 31 , 32 ]).…”

Biochemical and cellular basis of oxidative stress: Implications for disease onset

“…Peroxiredoxin‐1 acts redox‐relay in the activation of ASK1 (Vo et al, 2021). At high H 2 O 2 levels peroxiredoxin‐1 directly interacts with ASK1 (Vo et al, 2021), and inhibits ASK1‐induced apoptosis (Kim et al, 2008; Zhang et al, 2015). Peroxiredoxin‐1 has also been reported to directly interact with p53, c‐Myc, and nuclear factor kappa B (NF‐κB), among others (Ding et al, 2017).…”

“…Peroxiredoxin-1 acts redox-relay in the activation of ASK1 (Vo et al, 2021). At high H 2 O 2 levels peroxiredoxin-1 directly interacts with ASK1 (Vo et al, 2021), and inhibits ASK1-induced apoptosis (Kim et al, 2008;Zhang et al, 2015).…”

“…Hence, H 2 O 2 can act as an intracellular second messenger in signal transduction to modulate protein function by inducing the transient oxidation of protein cysteinyl thiols and the formation of disulfide bonds (Sobotta et al, 2015; Winterbourn & Hampton, 2015). Peroxiredoxin‐1 acts redox‐relay in the activation of ASK1 (Vo et al, 2021). At high H 2 O 2 levels peroxiredoxin‐1 directly interacts with ASK1 (Vo et al, 2021), and inhibits ASK1‐induced apoptosis (Kim et al, 2008; Zhang et al, 2015).…”