Myosin-binding protein C corrects an intrinsic inhomogeneity in cardiac excitation-contraction coupling.

ABSTRACT: The beating heart exhibits remarkable contractile fidelity over a lifetime, which reflects the tight coupling of electrical, chemical, and mechanical elements within the sarcomere, the elementary contractile unit. On a beat-to-beat basis, calcium is released from the ends of the sarcomere and must diffuse toward the sarcomere center to fully activate the myosin- and actin-based contractile proteins. The resultant spatial and temporal gradient in free calcium across the sarcomere should lead to nonuniform and inefficient activation of contraction. We show that myosin-binding protein C (MyBP-C), through its positioning on the myosin thick filaments, corrects this nonuniformity in calcium activation by exquisitely sensitizing the contractile apparatus to calcium in a manner that precisely cou

SUBMITTER: Previs MJ 

PROVIDER: S-EPMC4380226 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature