| Myosin filament polymerization and depolymerization in a model of partial length adaptation in airway smooth muscle. | |
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MedLine Citation:
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PMID: 21659490 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Length adaptation in airway smooth muscle (ASM) is attributed to reorganization of the cytoskeleton, and in particular the contractile elements. However, a constantly changing lung volume with tidal breathing (hence changing ASM length) is likely to restrict full adaptation of ASM for force generation. There is likely to be continuous length adaptation of ASM between states of incomplete or partial length adaption. We propose a new model that assimilates findings on myosin filament polymerization/depolymerization, partial length adaptation, isometric force, and shortening velocity to describe this continuous length adaptation process. In this model, the ASM adapts to an optimal force-generating capacity in a repeating cycle of events. Initially the myosin filament, shortened by prior length changes, associates with two longer actin filaments. The actin filaments are located adjacent to the myosin filaments, such that all myosin heads overlap with actin to permit maximal cross-bridge cycling. Since in this model the actin filaments are usually longer than myosin filaments, the excess length of the actin filament is located randomly with respect to the myosin filament. Once activated, the myosin filament elongates by polymerization along the actin filaments, with the growth limited by the overlap of the actin filaments. During relaxation, the myosin filaments dissociate from the actin filaments, and then the cycle repeats. This process causes a gradual adaptation of force and instantaneous adaptation of shortening velocity. Good agreement is found between model simulations and the experimental data depicting the relationship between force development, myosin filament density, or shortening velocity and length. |
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Authors:
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Gijs Ijpma; Ahmed M Al-Jumaily; Simeon P Cairns; Gary C Sieck |
Publication Detail:
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Type: Journal Article Date: 2011-06-09 |
Journal Detail:
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Title: Journal of applied physiology (Bethesda, Md. : 1985) Volume: 111 ISSN: 1522-1601 ISO Abbreviation: J. Appl. Physiol. Publication Date: 2011 Sep |
Date Detail:
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Created Date: 2011-09-09 Completed Date: 2012-01-11 Revised Date: 2012-03-05 |
Medline Journal Info:
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Nlm Unique ID: 8502536 Medline TA: J Appl Physiol Country: United States |
Other Details:
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Languages: eng Pagination: 735-42 Citation Subset: IM |
Affiliation:
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Institute of Biomedical Technologies, Auckland University of Technology, Auckland, New Zealand. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Actins
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metabolism Adaptation, Physiological Animals Biomechanics Cell Size* Compliance Cytoskeleton / metabolism* Humans Lung / cytology, metabolism* Models, Biological* Muscle Contraction* Muscle Strength Muscle, Smooth / cytology, metabolism* Myocytes, Smooth Muscle / metabolism* Myosins / metabolism* Protein Multimerization Reproducibility of Results Stochastic Processes Time Factors |
| Grant Support | |
ID/Acronym/Agency:
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R01 HL074309-08/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Actins; EC 3.6.4.1/Myosins |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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