title: Chaperone-mediated reversible inhibition of the sarcomeric myosin power stroke.
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.
authors.affiliation: Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, United States.
authors.forename: Paul
authors.initials: P
authors.lastname: Nicholls
authors.affiliation: Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, United States.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Bujalowski
authors.affiliation: Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, United States.
authors.forename: Henry F
authors.initials: HF
authors.lastname: Epstein
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, TX, United States.
authors.forename: Darren F
authors.initials: DF
authors.lastname: Boehning
authors.affiliation: Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, United States; Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, United States; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, United States. Electronic address: jmbarral@utmb.edu.
authors.forename: José M
authors.initials: JM
authors.lastname: Barral
authors.affiliation: Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, United States; Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, United States; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, United States. Electronic address: afoberha@utmb.edu.
authors.forename: Andres F
authors.initials: AF
authors.lastname: Oberhauser
mesh_terms: D000199:Actins / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000378:metabolism*; D051379:Mice; D018832:Molecular Chaperones; D009068:Movement; D009218:Myosins / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011817:Rabbits; D012518:Sarcomeres / Q000378:metabolism*
chemical_list: D000199:Actins; D018841:HSP90 Heat-Shock Proteins; D047908:Intracellular Signaling Peptides and Proteins; D018832:Molecular Chaperones; C529478:Unc45 protein, mouse; D000251:Adenosine Triphosphatases; D009218:Myosins
keywords: Actin-translocation; Chaperone; Hsp90; UNC-45