FBS Colloquia No.333Laboratory of Single Molecule Biology
| Seminar or Lecture |
Noise-induced acceleration of biomolecular motor kinesin Takayuki Ariga [Associate Professor, Laboratory of Single Molecule Biology] |
|---|---|
| Date and Time | 25 Jul. 2023 (Tue), 12:15～13:00 |
| Place | 3F Seminar Room, Nanobiology Bldg. |
| Language | Japanese |
| Contact |
Takayuki Ariga (Associate Professor) |
Noise-induced acceleration of biomolecular motor kinesin
Kinesin-1, a biomolecular motor that transports vesicles within the cell, has been proposed to efficiently achieve unidirectional movement by utilizing thermal fluctuation. Although the molecular mechanism of kinesin-1 has been clarified in detail by recent advances in single-molecule measurement techniques, its efficiency has been difficult to discuss due to its stochastic behavior.
We investigated the energy input/output of kinesin by measuring its velocity fluctuation and response (change in velocity when a small external force is applied) and quantifying its dissipation [1]. The results were surprising: kinesin appeared to be inefficient. On the other hand, the actual environment inside living cells was also found to be non-thermally fluctuating by consuming metabolic energy [2]. Based on these results, we hypothesized that kinesin would be optimized for the non-thermally fluctuating intracellular environment rather than the in vitro experimental conditions.
To investigate the effect of non-thermal fluctuations in the cell on kinesin motility, we artificially created fluctuations as external forces that mimic the intracellular fluctuations and measured the motility of a single-molecule kinesin while applying the force fluctuations [3]. As a result, we found that the fluctuation of the external force accelerates kinesin movement, especially under high load. This acceleration phenomenon was reproduced in a mathematical model. The universality of the theory behind the model suggested that this phenomenon occurs in general biomolecular machines.
In this colloquium, I would like to introduce these recent results and discuss the future development of our research, expanding the scope and hierarchy of our research with fluctuation and response as the key concepts.
[1] Ariga et al. Phys. Rev. Lett. 121, 218101 (2018), [2] Nishizawa et al. Sci. Adv. 3, e1700318 (2017), [3] Ariga et al. Phys. Rev. Lett., 127, 178101 (2021)
