Coordinated force generation of skeletal myosins in myofilaments through motor coupling
| Autor: | Hideo Higuchi, Yoshiaki Tani, Motoshi Kaya, Toshiaki Hisada, Takumi Washio |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Force generation Myofilament genetic structures Science Muscle Fibers Skeletal General Physics and Astronomy Nanotechnology macromolecular substances Myosins Models Biological Article General Biochemistry Genetics and Molecular Biology 03 medical and health sciences Adenosine Triphosphate 0302 clinical medicine Myofibrils Myosin medicine Molecular motor Animals Humans Computer Simulation Actin Physics Multidisciplinary Skeletal muscle General Chemistry Biomechanical Phenomena Adenosine Diphosphate Actin Cytoskeleton Kinetics 030104 developmental biology medicine.anatomical_structure Optical tweezers Biophysics medicine.symptom 030217 neurology & neurosurgery Muscle contraction |
| Zdroj: | Nature Communications, Vol 8, Iss 1, Pp 1-13 (2017) Nature Communications |
| ISSN: | 2041-1723 |
| Popis: | In contrast to processive molecular motors, skeletal myosins form a large motor ensemble for contraction of muscles against high loads. Despite numerous information on the molecular properties of skeletal myosin, its ensemble effects on collective force generation have not been rigorously clarified. Here we show 4 nm stepwise actin displacements generated by synthetic myofilaments beyond a load of 30 pN, implying that steps cannot be driven exclusively by single myosins, but potentially by coordinated force generations among multiple myosins. The simulation model shows that stepwise actin displacements are primarily caused by coordinated force generation among myosin molecules. Moreover, the probability of coordinated force generation can be enhanced against high loads by utilizing three factors: strain-dependent kinetics between force-generating states; multiple power stroke steps; and high ATP concentrations. Compared with other molecular motors, our findings reveal how the properties of skeletal myosin are tuned to perform cooperative force generation for efficient muscle contraction. Skeletal muscle myosin forms large ensembles to generate force against high loads. Using optical tweezers and simulation Kaya et al. provide experimental evidence for cooperative force generation, and describe how the molecular properties of skeletal myosins are tuned for coordinated power strokes. |
| Databáze: | OpenAIRE |
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