Abstract
Knowledge on the effects of divergent exercise on ostensibly protein degradation pathways may be valuable for counteracting muscle wasting and for understanding muscle remodelling. This study examined mRNA and/or protein levels of molecular markers of the ubiquitin proteasome pathway (UPP), including FBXO32 (atrogin-1), MURF-1, FBXO40, FOXO1 and FOXO3. Protein substrates of atrogin-1-including EIF3F, MYOG and MYOD1-and of MURF-1-including PKM and MHC-were also measured. Subjects completed 10 weeks of endurance training (ET) or resistance training (RT) followed by a single-bout of endurance exercise (EE) or resistance exercise (RE). Following training, atrogin-1, FBXO40, FOXO1 and FOXO3 mRNA increased independently of exercise mode, whereas MURF-1 mRNA and FOXO3 protein increased following ET only. No change in other target proteins occurred post-training. In the trained state, single-bout EE, but not RE, increased atrogin-1, MURF-1, FBXO40, FOXO1, FOXO3 mRNA and FOXO3 protein. In contrast to EE, FBXO40 mRNA and protein decreased following single-bout RE. MURF-1 and FOXO1 protein levels as well as the protein substrates of atrogin-1 and MURF-1 were unchanged following training and single-bout exercise. This study demonstrates that the intracellular signals elicited by ET and RT result in an upregulation of UPP molecular markers, with a greater increase following ET. However, in the trained state, the expression levels of UPP molecular markers are increased following single-bout EE, but are less responsive to single-bout RE. This suggests that adaptations following endurance exercise training are more reliant on protein UPP degradation processes than adaptations following resistance exercise training.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.