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arXiv · 1808.03469

Investigation of multiple-dynein transport of melanosomes by non-invasive force measurement using fluctuation unit $\chi$

Shin Hasegawa·Takashi Sagawa·Kazuho Ikeda·Yasushi Okada·Kumiko Hayashi
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Abstract

Pigment organelles known as melanosomes disperse or aggregate in a melanophore in response to hormones. These movements are mediated by the microtubule motors kinesin-2 and cytoplasmic dynein. However, the force generation mechanism of dynein, unlike that of kinesin, is not well understood. In this study, to address this issue, we investigated the dynein-mediated aggregation of melanosomes in zebrafish melanophores. We applied the fluctuation theorem of non-equilibrium statistical mechanics to estimate forces acting on melanosomes during transport by dynein, given that the energy of a system is related to its fluctuation. Our results demonstrate that multiple force-producing units cooperatively transport a single melanosome. Since the force is generated by dynein, this suggests that multiple dyneins carry a single melanosome. Cooperative transport has been reported for other organelles; thus, multiple-motor transport may be a universal mechanism for moving organelles within the cell.

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Shin Hasegawa, Takashi Sagawa, Kazuho Ikeda, Yasushi Okada, Kumiko Hayashi. 2018-08-10. Investigation of multiple-dynein transport of melanosomes by non-invasive force measurement using fluctuation unit $\chi$. https://doi.org/10.1016/j.bpj.2018.11.2216

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