Glutathione peroxidase-like protein that protects cells from phospholipid hydroperoxides and nonphospholipid peroxides during oxidative stress (PubMed:10480913, PubMed:11445588). Plays an important role in the oxidative stress-induced response in the presence of Ca(2+). Has peroxidase activity using preferentially thioredoxin as a reducing power. The redox state of the mitochondrial GPX2 is regulated by TRX1 and TRX2 (cytoplasmic thioredoxin), and by TRX3 (mitochondrial matrix thioredoxin) (PubMed:16251189). Involved in sporulation (PubMed:21763276). [thioredoxin]-dithiol + a hydroperoxide = [thioredoxin]-disulfide + an alcohol + H2O Monomer. By oxidative stress, dependent on transcription factor YAP1 (PubMed:10480913). By oleic acid (PubMed:21763276). Present with 2010 molecules/cell in log phase SD medium. The active site is a conserved redox-active cysteine residue, the peroxidatic cysteine (C(P)), which makes the nucleophilic attack on the peroxide substrate. The peroxide oxidizes the C(P)-SH to cysteine sulfenic acid (C(P)-SOH), which then reacts with another cysteine residue, the resolving cysteine (C(R)), to form a disulfide bridge. The disulfide is subsequently reduced by an appropriate electron donor to complete the catalytic cycle. In this atypical 2-Cys peroxiredoxin, C(R) is present in the same subunit to form an intramolecular disulfide. Belongs to the glutathione peroxidase family. Was originally thought to be a glutathione peroxidase (PubMed:10480913) or a phospholipid hydroperoxide glutathione peroxidase (PubMed:11445588), but functions as an atypical 2-Cys peroxiredoxin using thioredoxin as reducing power instead (PubMed:16251189).