Molecular Motors Activate Skeletal Muscle.

Area of Science:

• Biophysics
• Molecular Biology
• Cellular Physiology

Background:

• Skeletal muscle contraction is crucial for movement and can be impaired in various myopathies.
• Precise control over muscle contraction is needed for research and therapeutic interventions.
• Intracellular calcium signaling is a key regulator of muscle contraction.

Purpose of the Study:

• To investigate the application of light-activated molecular motors (MMs) for controlling skeletal muscle contraction.
• To explore the mechanism of MM-induced calcium release in muscle cells.
• To demonstrate the potential of this technique for studying and treating muscle dysfunction.

Main Methods:

• Utilized C2C12 myoblasts and differentiated myotubes.
• Activated molecular motors (MMs) using light to induce intracellular calcium release.
• Investigated the role of inositol trisphosphate (IP3)-mediated signaling and the cAMP pathway (adenylyl cyclase, protein kinase A).
• Observed localized myotube contraction upon MM activation.

Main Results:

• MMs successfully induced intracellular calcium release in C2C12 myoblasts and myotubes via IP3-mediated signaling.
• The calcium release magnitude was dependent on the unidirectional rotation of MMs.
• Inhibition of cAMP pathway proteins reduced the elicited calcium responses.
• Activated MMs caused localized contraction in differentiated C2C12 myotubes.

Conclusions:

• Light-activated molecular motors can precisely control skeletal muscle contraction at the single-cell level.
• This molecular mechanical technique provides a novel tool for studying muscle physiology and pathology.
• The findings open possibilities for developing new treatments for myopathies.