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Processive flow by biased polymerization mediates the slow axonal transport of actin
Classic pulse-chase studies have shown that actin is conveyed in slow axonal transport, but the mechanistic basis for this movement is unknown. Recently, we reported that axonal actin was surprisingly dynamic, with focal assembly/disassembly events (“actin hotspots”) and elongating polymers along th...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Rockefeller University Press
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6314539/ https://www.ncbi.nlm.nih.gov/pubmed/30401699 http://dx.doi.org/10.1083/jcb.201711022 |
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author | Chakrabarty, Nilaj Dubey, Pankaj Tang, Yong Ganguly, Archan Ladt, Kelsey Leterrier, Christophe Jung, Peter Roy, Subhojit |
author_facet | Chakrabarty, Nilaj Dubey, Pankaj Tang, Yong Ganguly, Archan Ladt, Kelsey Leterrier, Christophe Jung, Peter Roy, Subhojit |
author_sort | Chakrabarty, Nilaj |
collection | PubMed |
description | Classic pulse-chase studies have shown that actin is conveyed in slow axonal transport, but the mechanistic basis for this movement is unknown. Recently, we reported that axonal actin was surprisingly dynamic, with focal assembly/disassembly events (“actin hotspots”) and elongating polymers along the axon shaft (“actin trails”). Using a combination of live imaging, superresolution microscopy, and modeling, in this study, we explore how these dynamic structures can lead to processive transport of actin. We found relatively more actin trails elongated anterogradely as well as an overall slow, anterogradely biased flow of actin in axon shafts. Starting with first principles of monomer/filament assembly and incorporating imaging data, we generated a quantitative model simulating axonal hotspots and trails. Our simulations predict that the axonal actin dynamics indeed lead to a slow anterogradely biased flow of the population. Collectively, the data point to a surprising scenario where local assembly and biased polymerization generate the slow axonal transport of actin without involvement of microtubules (MTs) or MT-based motors. Mechanistically distinct from polymer sliding, this might be a general strategy to convey highly dynamic cytoskeletal cargoes. |
format | Online Article Text |
id | pubmed-6314539 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-63145392019-07-07 Processive flow by biased polymerization mediates the slow axonal transport of actin Chakrabarty, Nilaj Dubey, Pankaj Tang, Yong Ganguly, Archan Ladt, Kelsey Leterrier, Christophe Jung, Peter Roy, Subhojit J Cell Biol Research Articles Classic pulse-chase studies have shown that actin is conveyed in slow axonal transport, but the mechanistic basis for this movement is unknown. Recently, we reported that axonal actin was surprisingly dynamic, with focal assembly/disassembly events (“actin hotspots”) and elongating polymers along the axon shaft (“actin trails”). Using a combination of live imaging, superresolution microscopy, and modeling, in this study, we explore how these dynamic structures can lead to processive transport of actin. We found relatively more actin trails elongated anterogradely as well as an overall slow, anterogradely biased flow of actin in axon shafts. Starting with first principles of monomer/filament assembly and incorporating imaging data, we generated a quantitative model simulating axonal hotspots and trails. Our simulations predict that the axonal actin dynamics indeed lead to a slow anterogradely biased flow of the population. Collectively, the data point to a surprising scenario where local assembly and biased polymerization generate the slow axonal transport of actin without involvement of microtubules (MTs) or MT-based motors. Mechanistically distinct from polymer sliding, this might be a general strategy to convey highly dynamic cytoskeletal cargoes. Rockefeller University Press 2019-01-07 /pmc/articles/PMC6314539/ /pubmed/30401699 http://dx.doi.org/10.1083/jcb.201711022 Text en © 2018 Chakrabarty et al. http://www.rupress.org/terms/https://creativecommons.org/licenses/by-nc-sa/4.0/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 International license, as described at https://creativecommons.org/licenses/by-nc-sa/4.0/). |
spellingShingle | Research Articles Chakrabarty, Nilaj Dubey, Pankaj Tang, Yong Ganguly, Archan Ladt, Kelsey Leterrier, Christophe Jung, Peter Roy, Subhojit Processive flow by biased polymerization mediates the slow axonal transport of actin |
title | Processive flow by biased polymerization mediates the slow axonal transport of actin |
title_full | Processive flow by biased polymerization mediates the slow axonal transport of actin |
title_fullStr | Processive flow by biased polymerization mediates the slow axonal transport of actin |
title_full_unstemmed | Processive flow by biased polymerization mediates the slow axonal transport of actin |
title_short | Processive flow by biased polymerization mediates the slow axonal transport of actin |
title_sort | processive flow by biased polymerization mediates the slow axonal transport of actin |
topic | Research Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6314539/ https://www.ncbi.nlm.nih.gov/pubmed/30401699 http://dx.doi.org/10.1083/jcb.201711022 |
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