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Control of filament length by a depolymerizing gradient

Cells assemble microns-long filamentous structures from protein monomers that are nanometers in size. These structures are often highly dynamic, yet in order for them to function properly, cells maintain them at a precise length. Here we investigate length-dependent depolymerization as a mechanism o...

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Detalles Bibliográficos
Autores principales: Datta, Arnab, Harbage, David, Kondev, Jane
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7744062/
https://www.ncbi.nlm.nih.gov/pubmed/33275598
http://dx.doi.org/10.1371/journal.pcbi.1008440
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author Datta, Arnab
Harbage, David
Kondev, Jane
author_facet Datta, Arnab
Harbage, David
Kondev, Jane
author_sort Datta, Arnab
collection PubMed
description Cells assemble microns-long filamentous structures from protein monomers that are nanometers in size. These structures are often highly dynamic, yet in order for them to function properly, cells maintain them at a precise length. Here we investigate length-dependent depolymerization as a mechanism of length control. This mechanism has been recently proposed for flagellar length control in the single cell organisms Chlamydomonas and Giardia. Length dependent depolymerization can arise from a concentration gradient of a depolymerizing protein, such as kinesin-13 in Giardia, along the length of the flagellum. Two possible scenarios are considered: a linear and an exponential gradient of depolymerizing proteins. We compute analytically the probability distributions of filament lengths for both scenarios and show how these distributions are controlled by key biochemical parameters through a dimensionless number that we identify. In Chlamydomonas cells, the assembly dynamics of its two flagella are coupled via a shared pool of molecular components that are in limited supply, and so we investigate the effect of a limiting monomer pool on the length distributions. Finally, we compare our calculations to experiments. While the computed mean lengths are consistent with observations, the noise is two orders of magnitude smaller than the observed length fluctuations.
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spelling pubmed-77440622020-12-31 Control of filament length by a depolymerizing gradient Datta, Arnab Harbage, David Kondev, Jane PLoS Comput Biol Research Article Cells assemble microns-long filamentous structures from protein monomers that are nanometers in size. These structures are often highly dynamic, yet in order for them to function properly, cells maintain them at a precise length. Here we investigate length-dependent depolymerization as a mechanism of length control. This mechanism has been recently proposed for flagellar length control in the single cell organisms Chlamydomonas and Giardia. Length dependent depolymerization can arise from a concentration gradient of a depolymerizing protein, such as kinesin-13 in Giardia, along the length of the flagellum. Two possible scenarios are considered: a linear and an exponential gradient of depolymerizing proteins. We compute analytically the probability distributions of filament lengths for both scenarios and show how these distributions are controlled by key biochemical parameters through a dimensionless number that we identify. In Chlamydomonas cells, the assembly dynamics of its two flagella are coupled via a shared pool of molecular components that are in limited supply, and so we investigate the effect of a limiting monomer pool on the length distributions. Finally, we compare our calculations to experiments. While the computed mean lengths are consistent with observations, the noise is two orders of magnitude smaller than the observed length fluctuations. Public Library of Science 2020-12-04 /pmc/articles/PMC7744062/ /pubmed/33275598 http://dx.doi.org/10.1371/journal.pcbi.1008440 Text en © 2020 Datta et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Datta, Arnab
Harbage, David
Kondev, Jane
Control of filament length by a depolymerizing gradient
title Control of filament length by a depolymerizing gradient
title_full Control of filament length by a depolymerizing gradient
title_fullStr Control of filament length by a depolymerizing gradient
title_full_unstemmed Control of filament length by a depolymerizing gradient
title_short Control of filament length by a depolymerizing gradient
title_sort control of filament length by a depolymerizing gradient
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7744062/
https://www.ncbi.nlm.nih.gov/pubmed/33275598
http://dx.doi.org/10.1371/journal.pcbi.1008440
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