Myosin-binding protein C regulates the sarcomere lattice and stabilizes the OFF states of myosin heads.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38521794.
- Also identified by DOI 10.1038/s41467-024-46957-7 and PMC identifier 10960836.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Muscle contraction is produced via the interaction of myofilaments and is regulated so that muscle performance matches demand. Myosin-binding protein C (MyBP-C) is a long and flexible protein that is tightly bound to the thick filament at its C-terminal end (MyBP-C<sup>C8C10</sup>), but may be loosely bound at its middle- and N-terminal end (MyBP-C<sup>C1C7</sup>) to myosin heads and/or the thin filament. MyBP-C is thought to control muscle contraction via the regulation of myosin motors, as mutations lead to debilitating disease. We use a combination of mechanics and small-angle X-ray diffraction to study the immediate and selective removal of the MyBP-C<sup>C1C7</sup> domains of fast MyBP-C in permeabilized skeletal muscle. We show that cleavage leads to alterations in crossbridge kinetics and passive structural signatures of myofilaments that are indicative of a shift of myosin heads towards the ON state, highlighting the importance of MyBP-C<sup>C1C7</sup> to myofilament force production and regulation.
Medical subject headings
- Sarcomeres
- Carrier Proteins