PSMB5 and myocardial ischemia: Tian et al. (2012) reported mice that express a threonine 60 to alanine mutation on the proteasome subunit beta 5 (beta5T60A) to reduce the proteolytic activity of the proteasome had worsened myocardial ischemia-reperfusion injury. Impaired or insufficient proteasome activity has been associated with myocarditis (Szalay et al., 2006) and diabetic cardiomyopathy (Li and Wang, 2011). Genetic overexpression of key proteasome subunits enhances proteasome-mediated protein degradation and protects the heart against oxidative stress, proteotoxicity, and myocardial ischemia (Li et al., 2011a, b).