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Fission yeast tropomyosin specifies directed transport of myosin-V along actin cables
A hallmark of class-V myosins is their processivity—the ability to take multiple steps along actin filaments without dissociating. Our previous work suggested, however, that the fission yeast myosin-V (Myo52p) is a nonprocessive motor whose activity is enhanced by tropomyosin (Cdc8p). Here we invest...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The American Society for Cell Biology
2014
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3873894/ https://www.ncbi.nlm.nih.gov/pubmed/24196839 http://dx.doi.org/10.1091/mbc.E13-04-0200 |
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author | Clayton, Joseph E. Pollard, Luther W. Sckolnick, Maria Bookwalter, Carol S. Hodges, Alex R. Trybus, Kathleen M. Lord, Matthew |
author_facet | Clayton, Joseph E. Pollard, Luther W. Sckolnick, Maria Bookwalter, Carol S. Hodges, Alex R. Trybus, Kathleen M. Lord, Matthew |
author_sort | Clayton, Joseph E. |
collection | PubMed |
description | A hallmark of class-V myosins is their processivity—the ability to take multiple steps along actin filaments without dissociating. Our previous work suggested, however, that the fission yeast myosin-V (Myo52p) is a nonprocessive motor whose activity is enhanced by tropomyosin (Cdc8p). Here we investigate the molecular mechanism and physiological relevance of tropomyosin-mediated regulation of Myo52p transport, using a combination of in vitro and in vivo approaches. Single molecules of Myo52p, visualized by total internal reflection fluorescence microscopy, moved processively only when Cdc8p was present on actin filaments. Small ensembles of Myo52p bound to a quantum dot, mimicking the number of motors bound to physiological cargo, also required Cdc8p for continuous motion. Although a truncated form of Myo52p that lacked a cargo-binding domain failed to support function in vivo, it still underwent actin-dependent movement to polarized growth sites. This result suggests that truncated Myo52p lacking cargo, or single molecules of wild-type Myo52p with small cargoes, can undergo processive movement along actin-Cdc8p cables in vivo. Our findings outline a mechanism by which tropomyosin facilitates sorting of transport to specific actin tracks within the cell by switching on myosin processivity. |
format | Online Article Text |
id | pubmed-3873894 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2014 |
publisher | The American Society for Cell Biology |
record_format | MEDLINE/PubMed |
spelling | pubmed-38738942014-03-16 Fission yeast tropomyosin specifies directed transport of myosin-V along actin cables Clayton, Joseph E. Pollard, Luther W. Sckolnick, Maria Bookwalter, Carol S. Hodges, Alex R. Trybus, Kathleen M. Lord, Matthew Mol Biol Cell Articles A hallmark of class-V myosins is their processivity—the ability to take multiple steps along actin filaments without dissociating. Our previous work suggested, however, that the fission yeast myosin-V (Myo52p) is a nonprocessive motor whose activity is enhanced by tropomyosin (Cdc8p). Here we investigate the molecular mechanism and physiological relevance of tropomyosin-mediated regulation of Myo52p transport, using a combination of in vitro and in vivo approaches. Single molecules of Myo52p, visualized by total internal reflection fluorescence microscopy, moved processively only when Cdc8p was present on actin filaments. Small ensembles of Myo52p bound to a quantum dot, mimicking the number of motors bound to physiological cargo, also required Cdc8p for continuous motion. Although a truncated form of Myo52p that lacked a cargo-binding domain failed to support function in vivo, it still underwent actin-dependent movement to polarized growth sites. This result suggests that truncated Myo52p lacking cargo, or single molecules of wild-type Myo52p with small cargoes, can undergo processive movement along actin-Cdc8p cables in vivo. Our findings outline a mechanism by which tropomyosin facilitates sorting of transport to specific actin tracks within the cell by switching on myosin processivity. The American Society for Cell Biology 2014-01-01 /pmc/articles/PMC3873894/ /pubmed/24196839 http://dx.doi.org/10.1091/mbc.E13-04-0200 Text en © 2014 Clayton et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0). “ASCB®,” “The American Society for Cell Biology®,” and “Molecular Biology of the Cell®” are registered trademarks of The American Society of Cell Biology. |
spellingShingle | Articles Clayton, Joseph E. Pollard, Luther W. Sckolnick, Maria Bookwalter, Carol S. Hodges, Alex R. Trybus, Kathleen M. Lord, Matthew Fission yeast tropomyosin specifies directed transport of myosin-V along actin cables |
title | Fission yeast tropomyosin specifies directed transport of myosin-V along actin cables |
title_full | Fission yeast tropomyosin specifies directed transport of myosin-V along actin cables |
title_fullStr | Fission yeast tropomyosin specifies directed transport of myosin-V along actin cables |
title_full_unstemmed | Fission yeast tropomyosin specifies directed transport of myosin-V along actin cables |
title_short | Fission yeast tropomyosin specifies directed transport of myosin-V along actin cables |
title_sort | fission yeast tropomyosin specifies directed transport of myosin-v along actin cables |
topic | Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3873894/ https://www.ncbi.nlm.nih.gov/pubmed/24196839 http://dx.doi.org/10.1091/mbc.E13-04-0200 |
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