Thiol-specific peroxidase that catalyzes the reduction of hydrogen peroxide and organic hydroperoxides to water and alcohols, respectively (By similarity). Can reduce H(2)O(2) and short chain organic, fatty acid, and phospholipid hydroperoxides (By similarity). Also has phospholipase activity, and can therefore either reduce the oxidized sn-2 fatty acyl group of phospholipids (peroxidase activity) or hydrolyze the sn-2 ester bond of phospholipids (phospholipase activity) (By similarity). These activities are dependent on binding to phospholipids at acidic pH and to oxidized phospholipds at cytosolic pH (By similarity). Plays a role in cell protection against oxidative stress by detoxifying peroxides and in phospholipid homeostasis (By similarity). Exhibits acyl-CoA-dependent lysophospholipid acyltransferase which mediates the conversion of lysophosphatidylcholine (1-acyl-sn-glycero-3-phosphocholine or LPC) into phosphatidylcholine (1,2-diacyl-sn-glycero-3-phosphocholine or PC) (By similarity). Shows a clear preference for LPC as the lysophospholipid and for palmitoyl CoA as the fatty acyl substrate (By similarity). a hydroperoxide + 2 glutathione = an alcohol + glutathione disulfide + H2O a 1,2-diacyl-sn-glycero-3-phosphocholine + H2O = a 1-acyl-sn-glycero-3-phosphocholine + a fatty acid + H(+) a 1-acyl-sn-glycero-3-phosphocholine + an acyl-CoA = a 1,2-diacyl-sn-glycero-3-phosphocholine + CoA 1-hexadecanoyl-sn-glycero-3-phosphocholine + hexadecanoyl-CoA = 1,2-dihexadecanoyl-sn-glycero-3-phosphocholine + CoA 1,2-dihexadecanoyl-sn-glycero-3-phosphocholine + H2O = 1-hexadecanoyl-sn-glycero-3-phosphocholine + H(+) + hexadecanoate Homodimer (By similarity). Interacts with GSTP1; mediates PRDX6 glutathionylation and regeneration (By similarity). Interacts with APEX1. Interacts with STH. May interact with FAM168B (By similarity). May interact with HTR2A (By similarity). Also found in lung secretory organelles (lamellar bodies). Irreversibly inactivated by overoxidation of Cys-6 to sulfinic acid (Cys-SO(2)H) and sulfonic acid (Cys-SO(3)H) forms upon oxidative stress. Phosphorylation at Thr-177 by MAP kinases increases the phospholipase activity of the enzyme (By similarity). The phosphorylated form exhibits a greater lysophosphatidylcholine acyltransferase activity compared to the non-phosphorylated form (By similarity). 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 1-Cys peroxiredoxin, no C(R) is present and C(P) instead forms a disulfide with a cysteine from another protein or with a small thiol molecule. C(P) is reactivated by glutathionylation mediated by glutathione S-transferase Pi, followed by spontaneous reduction of the enzyme with glutathione. Belongs to the peroxiredoxin family. Prx6 subfamily.