Researchers from the Department of Nutrition, Exercise and Sport at the University of Copenhagen have shown that physical activity cleanses muscles when the protein ubiquitin marks and breaks down worn-out proteins. This prevents the accumulation of damaged proteins and helps keep muscles healthy.
Physical activity is beneficial to health in a number of ways, including building and maintaining healthy muscles, which are important to our ability to move around normally and to play the important role of regulating metabolism. Since most of the carbohydrate we eat is stored in muscles, our muscles are extremely important in regulating our metabolism.
An intense bike ride increases ubiquitin activity
Maintaining muscle function is essential. Part of our ability to do this depends on proteins – the building blocks of muscles – being broken down as we wear down and eliminated in a kind of cleansing process that allows them to replace them with freshly synthesized proteins.
Now, Danish researchers – in collaboration with research colleagues at the University of Sydney, Australia – have shown that a single, intense, 10-minute bike ride leads to a significant increase in the activity of ubiquitin, the “death marker protein”, and a subsequent intensification of targeting and the removal of worn out proteins in the muscles. This paves the way for the possible creation of new proteins:
“Muscles eliminate worn-out proteins in a number of ways,” explains Professor Erik Richter from the Department of Molecular Physiology in the UCPH’s Department of Nutrition, Exercise and Sport. He continues:
“One of these methods is when ubiquitin, the ‘death marker’, marks a protein in question. Ubiquitin itself is a small protein. It binds to the amino acid Lysine on worn proteins, after which the protein is transported to a proteasome, a structure that engulfs proteins and spits them out as they are
“class =” glossaryLink “> 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 own proteins. “
Why physical activity is healthy
While there is ample knowledge of how muscles regulate the build-up of new proteins during exercise, much less is known about how muscle contractions and exercise serve to significantly cleanse out worn-out proteins. Professor Bente Kiens, another project participant, stated, “The important role ubiquitin plays in cleaning up worn out proteins related to muscle activity has not been fully recognized. Now we know that physical activity increases the ubiquitin labeling of worn out proteins. “
Professor Jørgen Wojtaszewski, the third Danish participant in the project, explains that their results serve to strengthen the overall basis for the effects of physical activity: “Basically, this explains part of the reason why physical activity is healthy. The nice thing is that muscle use in and of itself triggers the processes that keep the muscles up to date, healthy and functional. “
There remains a large amount of knowledge that would be interesting to delve deeper into, as very little is known about how different training plans, gender, diet, and genetic background affect the process and, therefore, the possibility of having the influencing optimal muscle function.
The study was published in the prestigious FASEB Journal as a scientific article entitled “Quantification of Exercise-Regulated Ubiquitin Signaling in Human Skeletal Muscle Identifies Protein Modification Crosstalk Via NEDDylation”.
Reference: “Quantification of exercise-regulated ubiquitin signal in human skeletal muscle identifies protein modification crosstalk via NED dylation” by Benjamin L. Parker, Bente Kiens, Jørgen FP Wojtaszewski, Erik A. Richter and David E. James, March 5 2020, FASEB diary.
DOI: 10.1096 / fj.202000075R
Six healthy, untrained men between the ages of 26 and 28 completed an 8 to 11-minute training session on an exercise bike. Blood tests and muscle biopsies were taken before and after their training session was completed. The muscle biopsies were then examined by mass spectrometry, which showed how ubiquitin was used on a large scale to purify damaged proteins.
The study is funded by the Independent Research Fund Denmark and the Novo Nordisk Foundation.