Myosin V executes steps of variable length via structurally constrained diffusion
The molecular motor myosin V transports cargo by stepping on actin filaments, executing a random diffusive search for actin binding sites at each step. A recent experiment suggests that the joint between the myosin lever arms may not rotate freely, as assumed in earlier studies, but instead has a pr...
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doaj-d5fe11b4bb5f4267a880a955e2d3fbe12021-05-05T20:44:25ZengeLife Sciences Publications LtdeLife2050-084X2020-01-01910.7554/eLife.51569Myosin V executes steps of variable length via structurally constrained diffusionDavid Hathcock0https://orcid.org/0000-0003-4551-9239Riina Tehver1https://orcid.org/0000-0001-7406-3387Michael Hinczewski2https://orcid.org/0000-0003-2837-7697D Thirumalai3Department of Physics, Cornell University, Ithaca, United StatesDepartment of Physics and Astronomy, Denison University, Granville, United StatesDepartment of Physics, Case Western Reserve University, Cleveland, United StatesDepartment of Chemistry, University of Texas, Austin, United StatesThe molecular motor myosin V transports cargo by stepping on actin filaments, executing a random diffusive search for actin binding sites at each step. A recent experiment suggests that the joint between the myosin lever arms may not rotate freely, as assumed in earlier studies, but instead has a preferred angle giving rise to structurally constrained diffusion. We address this controversy through comprehensive analytical and numerical modeling of myosin V diffusion and stepping. When the joint is constrained, our model reproduces the experimentally observed diffusion, allowing us to estimate bounds on the constraint energy. We also test the consistency between the constrained diffusion model and previous measurements of step size distributions and the load dependence of various observable quantities. The theory lets us address the biological significance of the constrained joint and provides testable predictions of new myosin behaviors, including the stomp distribution and the run length under off-axis force.https://elifesciences.org/articles/51569myosin Vmotor proteinlever armactindiffusion |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
David Hathcock Riina Tehver Michael Hinczewski D Thirumalai |
spellingShingle |
David Hathcock Riina Tehver Michael Hinczewski D Thirumalai Myosin V executes steps of variable length via structurally constrained diffusion eLife myosin V motor protein lever arm actin diffusion |
author_facet |
David Hathcock Riina Tehver Michael Hinczewski D Thirumalai |
author_sort |
David Hathcock |
title |
Myosin V executes steps of variable length via structurally constrained diffusion |
title_short |
Myosin V executes steps of variable length via structurally constrained diffusion |
title_full |
Myosin V executes steps of variable length via structurally constrained diffusion |
title_fullStr |
Myosin V executes steps of variable length via structurally constrained diffusion |
title_full_unstemmed |
Myosin V executes steps of variable length via structurally constrained diffusion |
title_sort |
myosin v executes steps of variable length via structurally constrained diffusion |
publisher |
eLife Sciences Publications Ltd |
series |
eLife |
issn |
2050-084X |
publishDate |
2020-01-01 |
description |
The molecular motor myosin V transports cargo by stepping on actin filaments, executing a random diffusive search for actin binding sites at each step. A recent experiment suggests that the joint between the myosin lever arms may not rotate freely, as assumed in earlier studies, but instead has a preferred angle giving rise to structurally constrained diffusion. We address this controversy through comprehensive analytical and numerical modeling of myosin V diffusion and stepping. When the joint is constrained, our model reproduces the experimentally observed diffusion, allowing us to estimate bounds on the constraint energy. We also test the consistency between the constrained diffusion model and previous measurements of step size distributions and the load dependence of various observable quantities. The theory lets us address the biological significance of the constrained joint and provides testable predictions of new myosin behaviors, including the stomp distribution and the run length under off-axis force. |
topic |
myosin V motor protein lever arm actin diffusion |
url |
https://elifesciences.org/articles/51569 |
work_keys_str_mv |
AT davidhathcock myosinvexecutesstepsofvariablelengthviastructurallyconstraineddiffusion AT riinatehver myosinvexecutesstepsofvariablelengthviastructurallyconstraineddiffusion AT michaelhinczewski myosinvexecutesstepsofvariablelengthviastructurallyconstraineddiffusion AT dthirumalai myosinvexecutesstepsofvariablelengthviastructurallyconstraineddiffusion |
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1721458679595663360 |