Short bike rides drive "death marker protein" to refresh worn muscles
There’s no question that exercise is an important part of a healthy lifestyle, but there remains a lot to discover about the ways physical activity positively influences the human body. A new study has delved into the mechanics of muscle maintenance, finding that even short stints on a bike can boost the activity of the “death marker protein,” which clears out damage to keep things healthy and in working order.
The research was carried out by scientists at the University of Copenhagen and the University of Sydney and zeroes in on the role of a protein called ubiquitin. Previous research has highlighted the important role this protein plays as a type of “cellular vacuum cleaner,” tagging defective proteins for destruction so they can be replaced with fresh versions that function properly.
Studies have shown how exercise and fasting can supercharge this process, and the authors of the new study have uncovered new evidence of how even short spurts of physical activity can have an impact in this regard.
The team performed blood tests and muscle biopsies to examine the behavior of ubiquitin in healthy males before, during and after a single session of high-intensity exercise. Through this, the team found that a single, tough session on an exercise bike for around 10 minutes can drive a significant increase in ubiquitin activity, which in turn intensified the removal of worn-out and damaged proteins.
"Muscles eliminate worn-out proteins in several ways," explains Professor Erik Richter at the University of Copenhagen. "One of these methods is when ubiquitin, 'the death-marker,' tags a protein in question. Ubiquitin itself is a small protein. It attaches itself to the amino acid lysine on worn-out proteins, after which the protein is transported to a proteasome, which is a structure that gobbles up proteins and spits them out as amino acids. These amino acids can then be reused in the synthesis of new proteins. As such, ubiquitin contributes to a very sustainable circulation of the body's proteins.”
The researchers note that the maintenance of healthy muscle is important not just for strength and physical activity, but also plays a key role in regulating metabolism due to the large amounts of carbohydrates that it stores. Further, the findings advance our understanding of how muscle contractions during a quick hit of exercise can initiate this protein-removal process.
"Basically, it explains part of the reason why physical activity is healthy,” says Professor Jørgen Wojtaszewski from the University of Copenhagen. “The beauty is that muscle use, in and of itself, is what initiates the processes that keep muscles 'up to date', healthy and functional."
The research was published in the journal FASEB.
Source: University of Copenhagen