The peroxiredoxin Tpx1 is essential as a H202-scavenger during  aerobic growth in fission yeast

Jara, Mónica; Vivancos Prellezo, Ana; Calvo, Isabel A.; Moldón Vara, Alberto; Sansó Martínez, Miriam, 1979-; Hidalgo Hernando, Elena

doi:http://dx.doi.org/10.1091/mbc.E06-11-1039

The peroxiredoxin Tpx1 is essential as a H202-scavenger during aerobic growth in fission yeast

Citació

Jara M, Vivancos AP, Calvo IA, Moldón A, Sansó M, Hidalgo E. The peroxirredoxin Tpx1 is essential as a H202-scavenger during aerobic growth in fission yeast. Mol. Biol. Cell. 2007;18(6):2288-95. DOI: 10.1091/mbc.E06-11-1039

Resum

Peroxiredoxins are known to interact with hydrogen peroxide (H2O2) and to participate in oxidant scavenging, redox signal transduction, and heat-shock responses. The two-cysteine peroxiredoxin Tpx1 of Schizosaccharomyces pombe has been characterized as the H2O2 sensor that transduces the redox signal to the transcription factor Pap1. Here, we show that Tpx1 is essential for aerobic, but not anaerobic, growth. We demonstrate that Tpx1 has an exquisite sensitivity for its substrate, which explains its participation in maintaining low steady-state levels of H2O2. We also show in vitro and in vivo that inactivation of Tpx1 by oxidation of its catalytic cysteine to a sulfinic acid is always preceded by a sulfinic acid form in a covalently linked dimer, which may be important for understanding the kinetics of Tpx1 inactivation. Furthermore, we provide evidence that a strain expressing Tpx1.C169S, lacking the resolving cysteine, can sustain aerobic growth, and we show that small reductants can modulate the activity of the mutant protein in vitro, probably by supplying a thiol group to substitute for cysteine 169.