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Hydrophobicity variations along the surface of the coiled-coil rod may mediate striated muscle myosin assembly in Caenorhabditis elegans

Caenorhabditis elegans body wall muscle contains two isoforms of myosin heavy chain, MHC A and MHC B, that differ in their ability to initiate thick filament assembly. Whereas mutant animals that lack the major isoform, MHC B, have fewer thick filaments, mutant animals that lack the minor isoform, M...

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Detalles Bibliográficos
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1996
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2121044/
https://www.ncbi.nlm.nih.gov/pubmed/8896595
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description Caenorhabditis elegans body wall muscle contains two isoforms of myosin heavy chain, MHC A and MHC B, that differ in their ability to initiate thick filament assembly. Whereas mutant animals that lack the major isoform, MHC B, have fewer thick filaments, mutant animals that lack the minor isoform, MHC A, contain no normal thick filaments. MHC A, but not MHC B, is present at the center of the bipolar thick filament where initiation of assembly is thought to occur (Miller, D.M.,I. Ortiz, G.C. Berliner, and H.F. Epstein. 1983. Cell. 34:477-490). We mapped the sequences that confer A-specific function by constructing chimeric myosins and testing them in vivo. We have identified two distinct regions of the MHC A rod that are sufficient in chimeric myosins for filament initiation function. Within these regions, MHC A displays a more hydrophobic rod surface, making it more similar to paramyosin, which forms the thick filament core. We propose that these regions play an important role in filament initiation, perhaps mediating close contacts between MHC A and paramyosin in an antiparallel arrangement at the filament center. Furthermore, our analysis revealed that all striated muscle myosins show a characteristic variation in surface hydrophobicity along the length of the rod that may play an important role in driving assembly and determining the stagger at which dimers associate.
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spelling pubmed-21210442008-05-01 Hydrophobicity variations along the surface of the coiled-coil rod may mediate striated muscle myosin assembly in Caenorhabditis elegans J Cell Biol Articles Caenorhabditis elegans body wall muscle contains two isoforms of myosin heavy chain, MHC A and MHC B, that differ in their ability to initiate thick filament assembly. Whereas mutant animals that lack the major isoform, MHC B, have fewer thick filaments, mutant animals that lack the minor isoform, MHC A, contain no normal thick filaments. MHC A, but not MHC B, is present at the center of the bipolar thick filament where initiation of assembly is thought to occur (Miller, D.M.,I. Ortiz, G.C. Berliner, and H.F. Epstein. 1983. Cell. 34:477-490). We mapped the sequences that confer A-specific function by constructing chimeric myosins and testing them in vivo. We have identified two distinct regions of the MHC A rod that are sufficient in chimeric myosins for filament initiation function. Within these regions, MHC A displays a more hydrophobic rod surface, making it more similar to paramyosin, which forms the thick filament core. We propose that these regions play an important role in filament initiation, perhaps mediating close contacts between MHC A and paramyosin in an antiparallel arrangement at the filament center. Furthermore, our analysis revealed that all striated muscle myosins show a characteristic variation in surface hydrophobicity along the length of the rod that may play an important role in driving assembly and determining the stagger at which dimers associate. The Rockefeller University Press 1996-10-02 /pmc/articles/PMC2121044/ /pubmed/8896595 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Articles
Hydrophobicity variations along the surface of the coiled-coil rod may mediate striated muscle myosin assembly in Caenorhabditis elegans
title Hydrophobicity variations along the surface of the coiled-coil rod may mediate striated muscle myosin assembly in Caenorhabditis elegans
title_full Hydrophobicity variations along the surface of the coiled-coil rod may mediate striated muscle myosin assembly in Caenorhabditis elegans
title_fullStr Hydrophobicity variations along the surface of the coiled-coil rod may mediate striated muscle myosin assembly in Caenorhabditis elegans
title_full_unstemmed Hydrophobicity variations along the surface of the coiled-coil rod may mediate striated muscle myosin assembly in Caenorhabditis elegans
title_short Hydrophobicity variations along the surface of the coiled-coil rod may mediate striated muscle myosin assembly in Caenorhabditis elegans
title_sort hydrophobicity variations along the surface of the coiled-coil rod may mediate striated muscle myosin assembly in caenorhabditis elegans
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2121044/
https://www.ncbi.nlm.nih.gov/pubmed/8896595