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Main Authors: Ebata, H., Nishizawa, K., van Esterik, F. A. S., Tao, Y., Inokuchi, S., Ise, H., Mizuno, D.
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2504.18922
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author Ebata, H.
Nishizawa, K.
van Esterik, F. A. S.
Tao, Y.
Inokuchi, S.
Ise, H.
Mizuno, D.
author_facet Ebata, H.
Nishizawa, K.
van Esterik, F. A. S.
Tao, Y.
Inokuchi, S.
Ise, H.
Mizuno, D.
contents Cytoplasmic viscoelasticity is crucial for various intracellular processes. However, the dynamic shear modulus, $G(ω)$, has been reported to vary considerably, often without consistent patterns or rules, even within the same cell. Thus, uncovering the physical basis of cytoplasmic rheology, and whether any universal feature exists, remains a major challenge. Here, we employed microrheology with a 3D feedback technique to minimize artifacts such as laser phototoxicity and examined cytoplasmic viscoelasticity across varied mechanical environments, cell types, and cytoskeletal disruptions. Unlike previous studies, a single power-law rheology $G(ω)\propto(-iω)^{0.5}$ was observed over a broad frequency range for all conditions except ATP depletion. While the vimentin cytoskeleton significantly contributed to steady shear viscosity measured by pulling a particle over large distances, cytoskeletal disruptions had only a minor effect on locally measured viscoelasticity. These findings demonstrate that molecular crowding governs the observed universality, providing a framework to systematically investigate cytoplasmic mechanics across diverse cellular contexts.
format Preprint
id arxiv_https___arxiv_org_abs_2504_18922
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Single power-law rheology of crowded cytoplasm in living cells
Ebata, H.
Nishizawa, K.
van Esterik, F. A. S.
Tao, Y.
Inokuchi, S.
Ise, H.
Mizuno, D.
Biological Physics
Cytoplasmic viscoelasticity is crucial for various intracellular processes. However, the dynamic shear modulus, $G(ω)$, has been reported to vary considerably, often without consistent patterns or rules, even within the same cell. Thus, uncovering the physical basis of cytoplasmic rheology, and whether any universal feature exists, remains a major challenge. Here, we employed microrheology with a 3D feedback technique to minimize artifacts such as laser phototoxicity and examined cytoplasmic viscoelasticity across varied mechanical environments, cell types, and cytoskeletal disruptions. Unlike previous studies, a single power-law rheology $G(ω)\propto(-iω)^{0.5}$ was observed over a broad frequency range for all conditions except ATP depletion. While the vimentin cytoskeleton significantly contributed to steady shear viscosity measured by pulling a particle over large distances, cytoskeletal disruptions had only a minor effect on locally measured viscoelasticity. These findings demonstrate that molecular crowding governs the observed universality, providing a framework to systematically investigate cytoplasmic mechanics across diverse cellular contexts.
title Single power-law rheology of crowded cytoplasm in living cells
topic Biological Physics
url https://arxiv.org/abs/2504.18922