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Direct visualization of myosin-binding protein C bridging myosin and actin filaments in intact muscle.

ABSTRACT: Myosin-binding protein C (MyBP-C) is a thick filament protein playing an essential role in muscle contraction, and MyBP-C mutations cause heart and skeletal muscle disease in millions worldwide. Despite its discovery 40 y ago, the mechanism of MyBP-C function remains unknown. In vitro studies suggest that MyBP-C could regulate contraction in a unique way--by bridging thick and thin filaments--but there has been no evidence for this in vivo. Here we use electron tomography of exceptionally well preserved muscle to demonstrate that MyBP-C does indeed bind to actin in intact muscle. This binding implies a physical mechanism for communicating the relative sliding between thick and thin filaments that does not involve myosin and which could modulate the contractile process.

SUBMITTER: Luther PK

PROVIDER: S-EPMC3136262 | biostudies-other | 2011 Jul

REPOSITORIES: biostudies-other

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Direct visualization of myosin-binding protein C bridging myosin and actin filaments in intact muscle.

Luther Pradeep K PK Winkler Hanspeter H Taylor Kenneth K Zoghbi Maria E ME Craig Roger R Padrón Raúl R Squire John M JM Squire John M JM Liu Jun J

Proceedings of the National Academy of Sciences of the United States of America 20110624 28

Myosin-binding protein C (MyBP-C) is a thick filament protein playing an essential role in muscle contraction, and MyBP-C mutations cause heart and skeletal muscle disease in millions worldwide. Despite its discovery 40 y ago, the mechanism of MyBP-C function remains unknown. In vitro studies suggest that MyBP-C could regulate contraction in a unique way--by bridging thick and thin filaments--but there has been no evidence for this in vivo. Here we use electron tomography of exceptionally well p ...[more]

PMID: 21705660

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