How muscles repair and grow at the same time
The cochaperone BAG3 coordinates protein synthesis and autophagy under mechanical strain through spatial regulation of mTORC1.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
mTORC1 is inhibited locally at damage sites but activated in the cytoplasm during the same mechanical strain event.
mTORC1 is widely seen as a universal ‘growth on’ switch—this study shows it’s spatially controlled, meaning it can be off in one part of the cell and on in another simultaneously.
Practical Takeaways
Focus on consistent mechanical loading (e.g., resistance training) to activate the BAG3-mTORC1 pathway, even if you don’t feel sore.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
mTORC1 is inhibited locally at damage sites but activated in the cytoplasm during the same mechanical strain event.
mTORC1 is widely seen as a universal ‘growth on’ switch—this study shows it’s spatially controlled, meaning it can be off in one part of the cell and on in another simultaneously.
Practical Takeaways
Focus on consistent mechanical loading (e.g., resistance training) to activate the BAG3-mTORC1 pathway, even if you don’t feel sore.
Publication
Journal
Biochimica et biophysica acta. Molecular cell research
Year
2017
Authors
Barbara Kathage, S. Gehlert, Anna Ulbricht, Laura Lüdecke, Victor E. Tapia, Z. Orfanos, D. Wenzel, W. Bloch, R. Volkmer, B. Fleischmann, D. Fürst, J. Höhfeld
Related Content
Claims (6)
When you lift weights, it's the pulling force on your muscles—not the tears or burn—that makes them grow bigger, and scientists think a specific molecular signal inside the muscle cells is behind this growth; other things like soreness or muscle burn probably don't cause the growth on their own.
When cells are stretched or pushed, a protein called BAG3 grabs onto two other proteins (TSC1/TSC2) that normally slow down protein production. This lets the cell make more proteins, as if it’s hitting the gas pedal.
When cells get stretched or squeezed, a protein called BAG3 helps the cell clean up damaged parts and make new proteins at the same time, keeping everything balanced and working properly.
A protein called BAG3 acts like a magnet to grab another protein called TSC1, and together they help move a team of proteins to special cable-like structures in cells when those cells are stretched or pulled.
When a cell gets stretched and its internal scaffolding gets damaged, it needs to turn off a specific molecular brake (mTORC1) right where the damage happened to start cleaning up the mess — otherwise, it won’t begin its self-repair process.