The Role of Src Kinase in Macrophage-Mediated Inflammatory Responses

Figure 5

The role of Src under conditions of oxidative stress. Src has been shown to control NADPH oxidase activation and ROS production. NADPH oxidase is an enzymatic component of the production of ROS under various pathologic conditions. Activated NADPH oxidase is a multimeric protein consisting of at least three cytosolic subunits: p47phox, p67phox, and p40phox. The p47phox subunit plays a significant role in the acute activation of NADPH oxidase; the phosphorylation of p47phox is thought to inhibit intracellular interactions and promote the binding of p47phox to p22phox, thereby inducing the activation of NADPH oxidase. The expression of phase II and antioxidant enzymes is a defense mechanism that protects tissues from injury by ROS production. The phase II enzymes include the heme oxygenase-1 (HO-1), NADPH quinine oxidoreductase (NQO1), glutathione S-transferase (GST), and superoxide dismutase (SOD). These enzymes are expressed following NRF2 binding to the antioxidant response element (ARE).