Page 1 of 3

© 20xxJAPAN
2021 THE BIOPHYSICAL SOCIETY OF JAPANAdvanceVol.
pp.Publication
1–3(20xx)(2021)
Vol. XX,
pp.18,xxx-xxx
doi:doi:
10.2142/biophysico.bppb-vXX.XXX
10.2142/biophysico.bppb-v18.026

Biophysics and Physicobiology

https://www.jstage.jst.go.jp/browse/biophysico/Commentary and Perspective

Japan-US symposium on cytoskeletal motor proteins and theirassociated proteins
Kumiko Hayashi1, Shinsuke Niwa2,3
123

Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan
Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, Sendai, Miyagi 980-0845, Japan
Graduate School of Life Science, Tohoku University, Sendai, Miyagi 980-8578, Japan

Received September
2021;
Accepted
October
2021;
Month date,28,year;
AcceptedMonthdate,1,year;
Released online in J-STAGE as advance publication October
6, 2021Month date,year
Editor Name
Edited by HarukiNakamura
Over the last decade, the Biophysical Society of Japan [1] has encouraged holding exchange symposiums among
overseas countries. So far, such symposiums were held with Asian countries mainly because in-person meetings werepreconditions and Asian countries are geographically close to Japan. Under the pandemic situation, this precondition canbe released by the possibility of virtual meetings. It is easier for us to attend international conferences online. Considering
this as a merit of the pandemic situation, this time, for the 59th Annual Meeting of the Biophysical Society of Japan, weplan to conduct a joint virtual symposium between Japan and the USA. We would like to state that the annual meeting
was first thought to be held in person in Sendai, in 2021, commemorating the 10th anniversary of the Great East JapanEarthquake. Sendai was one of the areas affected by the disaster. The meeting will be held as a symbol of the recoveryof our society from the earthquake and COVID-19 pandemic.
In the illustration of a cell for the webpage of the annual meeting (Fig. 1), one can see myosin fibers pulling actin
filaments together, kinesin and dynein walk along microtubules transporting mitochondria and endosomes, and FoF1ATP synthase rotates synthesizing ATP molecules inside the mitochondrion. Studies on these motor proteins are topicsof the symposium. Speakers in this symposium are recognized internationally as experts in the field of motor proteins
and their associated proteins. The symposium topics include multidisciplinary applications of genetics, bio-engineering,bio-chemistry, medical science, and physics of motor proteins, which will give us new insights into the motor proteins,
as well as novel applications of existing single-molecule techniques.
We have invited three speakers from the United States. Dr. Zev Bryant (Stanford University) will talk about engineering
biomolecular motors. He describes the work of his group and their findings by saying “Molecular motors lie at the heartof biological processes ranging from DNA replication to cell migration. We use single-molecule tracking andmanipulation to characterize the structural dynamics of these nanoscale assemblies, and further challenge ourunderstanding by designing and testing structural variants with novel properties that expand the functional range ofknown biomolecular machines. In the process, we are developing an engineering capacity for molecular motors withtunable and dynamically controllable physical properties, providing a toolkit for precise perturbations of mechanicalfunctions in vitro and in living cells.” See details of the Bryant lab [2] and a recent publication [3].
Dr. Erika Holzbaur (University of Pennsylvania) will talk about deciphering the function of activating adaptors in themotor-driven transport of mitochondria and autophagosomes. She summarizes the work of her group by saying “Theaxons of neurons are maintained by the active transport of organelles along the microtubule cytoskeleton, driven by themolecular motors cytoplasmic dynein and kinesin. Organelles such as mitochondria and autophagosomes co-purify withboth dynein and kinesin motors, which independently drive movement to either the microtubule minus- or plus-end. We
are interested in how the activities of opposing dynein and kinesin motors are coordinately regulated on an organelle byCorresponding author: Kumiko Hayashi, Graduate School of Engineering, Tohoku University, 6-6-05 Aoba, Aramaki,Aoba-ku, Sendai, Miyagi 980-8579, Japan. ORCID iD: https://orcid.org/0000-0002-2895-8945, e-mail:kumiko.hayashi.a2@tohoku.ac.jp

Page 2 of 3

2 Biophysics and Physicobiology Vol. 18
page-number Biophysics and Physicobiology Vol. XX
adaptor and scaffolding proteins. Here, I will focus on the role of TRAK2 in regulating dynein and kinesin motors on
mitochondria, and the role of HAP1 in regulating motors on autophagosomes, using single molecule assays and live cell
imaging to better understand organelle transport in neurons.” See details of the Holzbaur lab [4] and a recent publication[5].
Dr. Kristen Verhey (University of Michigan) will talk about a rogue kinesin that destroys microtubules in cells. She
describes the breakthroughs made in her laboratory by saying “Recent work on kinesins has raised the possibility thatthe physical act of motors walking on microtubules creates stress in the microtubule lattice. Whether processive motilityof kinesin and/or dynein motors creates stress and/or defects in the microtubule lattice in cells has not been determined.
Here, we describe a kinesin-1 mutant that causes microtubule destruction when expressed in cells. Using in vitro assays,
we show that the mutant motor is unable to promote rescues in microtubule dynamics assays and generates large defects
in the microtubule lattice in microtubule repair assays. These findings suggest that the mutant is an unnatural or rogue
motor whose activity would have been selected against during evolution.” See the details of the Verhey lab [6] and a
recent publication [7].
From the Japanese perspective, recent studies from three laboratories have been introduced. Dr. Ryohei Kobayashi
from the Hiroyuki Noji lab [8] discusses the single-molecule experiment on IF1, a regulatory protein of mitochondrial
ATP synthase [9]; Dr. Jakia Jannet Keya from the Ryota Iino lab [10] talks about engineering hybrid kinesin with asynthetic linker [11]; and Dr. Shinsuke Niwa, sharing the talk with Dr. Kyoko Chiba from the Shinsuke Niwa lab [12],provides topics on genetics using C. elegans and single-molecule experiments with several types of kinesin [13,14]. Dr.
Kumiko Hayashi [15], who is a member of both the Biophysical Society [16] and the Biophsyical Society of Japan [1],is the moderator and overall host of the joint symposium, promoting debates from an interdisciplinary point of view. We
hope that the joint symposium will promote the exchanges of ideas between the research communities of Japan and theUSA.

Figure 1 (Left) Proteins working in a cell, fromthe 59th annual meeting of the BiophysicalSociety of Japan [17]. (Right) 2021 is the 10thanniversary of the Great East Japan Earthquake.
The meeting is held to mark the recovery of oursociety from the earthquake and COVID-19
pandemic, aimed at enabling new biophysicalfindings through collaborations, while thrivingon adversity.
References[1] The Biophysical Scosity of Japan https://www.biophys.jp/index-e.html[2] Zev Bryant lab (Stanford University) https://bryantlab.stanford.edu/[3] Ruijgrok, P. V., Ghosh, R. P., Zemsky, S., Nakamura, M., Gong, R., Lin, N., et al. Optical control of fast andprocessive engineered myosins in vitro and in living cells. Nat. Chem. Biol. 17, 540-548 (2021).
https://doi.org/10.1038/s41589-021-00740-7[4] Erika Holzbaur lab (University of Pennsylvania) https://www.med.upenn.edu/holzbaurlab[5] Fenton, A. R., Jongens, T. A., Holzbaur, E. L. F. Mitochondrial dynamics: Shaping and remodeling an organelle
network. Curr. Opin. Cell Biol. 68, 28-36 (2021). https://doi.org/10.1016/j.ceb.2020.08.014[6] Kristen Verhey lab (University of Michigan) https://verheylab.org/[7] Budaitis, B. G., Jariwala, S., Rao, L., Yue, Y., Sept, D., Verhey, K. J., et. al. Pathogenic mutations in the kinesin3 motor KIF1A diminish force generation and movement through allosteric mechanisms. J. Cell Biol. 220,

Page 3 of 3[42] Bakan, A., Meireles, L. M. & Bahar, I. ProDy: Protein Dynamics Inferred from Theory and Experiments.
Bioinformatics 27, 1575–1577 (2011). DOI: 10.1093/bioinformatics/btr168[43] Humphrey, W., Dalke, A. & Schulten, K. VMD: Visual molecular dynamics. J. Mol. Graph. 14, 33–38 (1996).
DOI: 10.1016/0263-7855(96)00018-5[44] McGibbon, R. T., Beauchamp, K. A., Harrigan, M. P., Klein, C., Swails, J. M., Hernández, C. X., et al. MDTraj: A
Modern Open Library for the Analysis of Molecular Dynamics Trajectories. Biophys. J. 109, 1528–1532 (2015).
Hayashi et al. 3
DOI: 10.1016/j.bpj.2015.08.015
Xxxxx et al.: page-number[45] Best, R. B., Hummer, G. & Eaton, W. A. Native contacts determine protein folding mechanisms in atomistic
e202004227(2021).
simulations.
Proc.
Natl.https://doi.org/10.1083/jcb.202004227
Acad. Sci. USA 110, 17874–17879 (2013). DOI: 10.1073/pnas.1311599110[8] Abe,HiroyukiNoji labof Tokyo)[46]
K., Kabe,Y., (UniversityUchiyama, S.,Iwasaki,http://www.nojilab.t.u-tokyo.ac.jp/eng/
Y. W., Ishizu, H., Uwamino, Y., et al. Pro108Ser mutant of SARS[9] CoV-2
Kobayashi,Mori,theS., enzymaticUeno, H., Noji,H. andKinetic
analysis COVID-19of the inhibition
mechanism
bovine mitochondrial
3CLproR.,
reduces
activity
ameliorates
severityin Japan.ofmedRxiv(2021). DOI:
-ATPaseinhibitory
proteinusing
biochemical
assay.
J.
Biochem,
170,
79-87(2021).
F1
10.1101/2020.11.24.20235952
https://doi.org/10.1093/jb/mvab022[47] Świderek,
K. & Moliner, V. Revealing the molecular mechanisms of proteolysis of SARS-CoV-2 M pro by[10]QM/MM
Ryota Iinolab (Institutemethods.
for Molecular
https://groups.ims.ac.jp/organization/iino_g/index.html
computationalChem.Science)
Sci. 11, 10626–10630(2020). DOI: 10.1039/D0SC02823A[11]Iino,R.,
Kinbara,K.,
Bryant,Z.
Introduction:
Molecular
Motors. Chem.
Rev. 120,[48] Kuhlman, B. & Bradley, P. Advances in protein structure prediction
and design.
Nat.1-4
Rev.(2020).
Mol. Cell Biol. 20, 681–
https://doi.org/10.1021/acs.chemrev.9b00819
697 (2019). DOI: 10.1038/s41580-019-0163-x[12] Shinsuke Niwa lab (Tohoku University) http://www.fris.tohoku.ac.jp/~niwa/ (Japanese only)[49] Kuroda, D. & Tsumoto, K. Engineering Stability, Viscosity, and Immunogenicity of Antibodies by Computational[13] Anazawa, Y., Kita, T., Hayashi, K., Niwa, S. De novo disease-associated mutations in KIF1A dominant negatively inhibit
Design. J. Pharm. Sci. 109, 1631–1651 (2020). DOI: 10.1016/j.xphs.2020.01.011
axonal transport of synaptic vesicle precursors. bioRxiv (2021). https://doi.org/10.1101/2021.07.22.453457[50] Kuroda, D., Shirai, H., Jacobson, M. P. & Nakamura, H. Computer-aided antibody design. Protein Eng. Des. Sel.
[14] Chiba, K., Ori-McKenney, K. M., Niwa, S., McKenney, R. J. Reconstitution of Kinesin-1 Activation. bioRxiv (2021).
25,
507–521 (2012). DOI: 10.1093/protein/gzs024
https://dor.org/10.1101/2021.03.12.434960[51]Leman,
J. K., Weitzner,
B. (Tohoku
D., Lewis,
S. M., Adolf-Bryfogle,J., Alam, N., Alford, R. F., et al. Macromolecular[15] Mathematical
Physics labUniversity)
http://web.tohoku.ac.jp/mathphys/en/modeling
anddesignin
Rosetta:recentmethods
andframeworks.
Nat. Methods 17, 665–680 (2020). DOI:
[16] Biophysical Society https://www.biophysics.org/10.1038/s41592-020-0848-2
th[17] 59 annual meeting of the Biophysical Society of Japan https://www2.aeplan.co.jp/bsj2021/english/index.html
This article is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
To view a copy of this license, visit https://creativecommons.org/licenses/by-nc-sa/4.0/.