Three-dimensional reconstruction of tarantula myosin filaments suggests how phosphorylation may regulate myosin activity.

ABSTRACT: Muscle contraction involves the interaction of the myosin heads of the thick filaments with actin subunits of the thin filaments. Relaxation occurs when this interaction is blocked by molecular switches on these filaments. In many muscles, myosin-linked regulation involves phosphorylation of the myosin regulatory light chains (RLCs). Electron microscopy of vertebrate smooth muscle myosin molecules (regulated by phosphorylation) has provided insight into the relaxed structure, revealing that myosin is switched off by intramolecular interactions between its two heads, the free head and the blocked head. Three-dimensional reconstruction of frozen-hydrated specimens revealed that this asymmetric head interaction is also present in native thick filaments of tarantula striated muscle. Our goal i

SUBMITTER: Alamo L 

PROVIDER: S-EPMC2729561 | biostudies-literature | 2008 Dec

REPOSITORIES: biostudies-literature