Module 2: Figure ROS formation and action
Formation of H2O2 and its action to regulate phosphotyrosine phosphatase (PTP) and phosphatase and tensin homologue deleted on chromosome 10 (PTEN).
The hydrogen peroxide (H2O2) formed by the NADPH oxidase (NOX)/DUOX (dual oxidase) complex creates a microdomain in which it can inactivate enzymes involved in various signalling pathways: 1. The phosphotyrosine phosphatase (PTP) that dephosphorylates various signalling proteins is inactivated following its oxidation by H2O2; 2. The inositol lipid phosphatase and tensin homologue deleted on chromosome 10 (PTEN), which dephosphorylates the lipid second messenger PtdIns3,4,5P3, is inactivated following its oxidation by H2O2. These two enzymes can be reactivated following their reduction by the thioredoxin (Trx) system (Module 2: Figure recovery of protein oxidation).