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Updated: Apr 23, 2026

Dissecting Mechanoenzymatic Properties of Processive Myosins with Ultrafast Force-Clamp Spectroscopy
Published on: July 1, 2021
Chaperone-mediated reversible inhibition of the sarcomeric myosin power stroke
Paul Nicholls1, Paul J Bujalowski1, Henry F Epstein1
1Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, United States.
Abstract:
Molecular chaperones are required for successful folding and assembly of sarcomeric myosin in skeletal and cardiac muscle. Here, we show that the chaperone UNC-45B inhibits the actin translocation function of myosin. Further, we show that Hsp90, another chaperone involved in sarcomere development, allows the myosin to resume actin translocation. These previously unknown activities may play a key role in sarcomere development, preventing untimely myosin powerstrokes from disrupting the precise alignment of the sarcomere until it has formed completely.
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