TRIM63 and myocardial infarction: Furthermore, protein and mRNA expressions of Hsp90 and MuRF1, two key factors that participate in ubiquitin degradation of proteins in myocardium [27,28] significantly increased in the MI group (p < 0.01 vs. the S group, Figure 2H–K) and was downregulated in the MI + EX group (p < 0.01 vs. the MI group), indicating an inhibitory effect of exercise training on ubiquitin degradation of proteins in post-MI hearts.