Open AccessCoordinated force generation of skeletal myosins in myofilaments through motor coupling
Author(s) -
Mitsunori Kaya,
Yoshiaki Tani,
Takumi Washio,
Toshiaki Hisada,
Hideo Higuchi
Publication year - 2017
Publication title -
nature communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.559
H-Index - 365
ISSN - 2041-1723
DOI - 10.1038/ncomms16036
Subject(s) - myofilament , myosin , actin , molecular motor , skeletal muscle , biophysics , muscle contraction , motor protein , coupling (piping) , contraction (grammar) , chemistry , physics , materials science , biology , anatomy , biochemistry , microbiology and biotechnology , metallurgy , endocrinology , microtubule
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.