| First Author | Matravadia S | Year | 2013 |
| Journal | Am J Physiol Regul Integr Comp Physiol | Volume | 305 |
| Issue | 7 | Pages | R822-31 |
| PubMed ID | 23904104 | Mgi Jnum | J:240728 |
| Mgi Id | MGI:5888980 | Doi | 10.1152/ajpregu.00590.2012 |
| Citation | Matravadia S, et al. (2013) Exercise training increases the expression and nuclear localization of mRNA destabilizing proteins in skeletal muscle. Am J Physiol Regul Integr Comp Physiol 305(7):R822-31 |
| abstractText | While a paucity of information exists regarding posttranscriptional mechanisms influencing mitochondrial biogenesis, in resting muscle the stability of peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1alpha) mRNA has been linked to mitochondrial content. Therefore, in the current study we have examined whether exercise promotes mRNA accumulation through the induction of proteins affiliated with mRNA stabilization (human antigen R, HuR) or conversely by decreasing the expression of mRNA destabilizing proteins [AU-rich binding factor (AUF1) and CUG binding protein (CUG-BP1)]. A single bout of exercise increased (P < 0.05) the mRNA content of the transcriptional coactivator PGC-1alpha approximately 3.5-fold without affecting mRNA content for HuR, CUG-BP1, or AUF1. One week of treadmill exercise training did not alter markers of mitochondrial content, the mRNA stabilizing protein HuR, or the mRNA destabilizing protein AUF1. In contrast, the mRNA destabilizing protein CUG-BP1 increased approximately 40%. Four weeks of treadmill training increased the content of subunits of the electron transport chain approximately 50%, suggesting induction of mitochondrial biogenesis. Expression levels for HuR and CUG-BP1 were not altered with chronic training; however, AUF1 expression was increased posttraining. Specifically, training increased (P < 0.05) total muscle expression of two of four AUF1 isoforms approximately 50% (AUF1(p37), AUF1(p40)). Interestingly, these two isoforms were not detected in isolated nuclei; however, a large band representing the other two isoforms (AUF1(p42), AUF1(p45)) was present in nuclei and increased approximately 35% following chronic training. Altogether the current data provides evidence that mitochondrial biogenesis occurs in the presence of increased CUG-BP1 and AUF1, suggesting that reductions in known mRNA destabilizing proteins likely does not contribute to exercise-induced mitochondrial biogenesis. |
