Article
Dependence of thick filament structure in relaxed mammalian skeletal muscle on temperature and interfilament spacing
Caremani et al. use x-ray diffraction and interference to characterize the structure of thick filaments in relaxed demembranated and intact resting mammalian muscle, revealing two closely spaced axial periodicities as well as structural changes that occur when filament activation is mimicked by cooling below near-physiological temperature.
Evidence for S2 flexibility by direct visualization of quantum dot–labeled myosin heads and rods within smooth muscle myosin filaments moving on actin in vitro
Brizendine et al. directly visualized quantum dot–labeled myosin heads and rods in vitro to understand the flexibility of the S2 subdomain. Their results confirm theoretical predictions about the range of motion of S2 and its effect on the relative movement of myosin on actin in vitro.
The number of Z-repeats and super-repeats in nebulin greatly varies across vertebrates and scales with animal size
Gohlke et al. compare the structure of the sarcomeric protein nebulin across 53 species. They uncover an association between the number of nebulin structural repeats and animal body size that has implications for muscle mechanics.
Viewpoint
Making waves: A proposed new role for myosin-binding protein C in regulating oscillatory contractions in vertebrate striated muscle
A new role for myosin-binding protein C in damping sarcomere force oscillations is proposed that has implications for mechanical feedback and cell-to-cell communication in the heart.
