Abstract
Commentaries on the section “Applications of Non-equilibrium Physics” of the 21st IUPAB Congress 2024 were presented. The abstract and presentations of the session were briefly introduced. This session brought together leading researchers to discuss the latest advancements and applications of non-equilibrium physics in biological systems. The talks highlighted the theoretical and experimental approaches used to explore non-equilibrium phenomena, including energy transduction, self-organization, and dynamic stability in complex biological structures. This session provided a comprehensive overview of the current state of non-equilibrium physics in biophysics, fostering interdisciplinary collaboration and setting the stage for future research directions in this rapidly evolving field.
The 21st IUPAB Congress, held in Kyoto, Japan, in 2024, featured a dedicated session on the “Application of Non-equilibrium Physics,” with a special focus on theoretical and computational approaches for studying active matter and biophysical systems at various scales, including proteins and cells. This session delved into the forefront of non-equilibrium statistical and biophysics, examining phenomena such as stochastic thermodynamics, fluctuation theorems, and dynamical systems. The session consisted of four invited talks and two pick-up talks from young researchers (Fig. 1). First, the lecture contents of the invited speakers were as follows.
Fig. 1.
Speakers and chairs of the session “Application of Non-equilibrium Physics” of the 21th IUPAB Congress 2024 held in Kyoto, Japan, on June 27, 2024
Dr. Takayuki Ariga (Osaka University) discussed non-equilibrium energetics on a motor protein, which is represented by the Harada-Sasa equality (Harada and Sasa 2005), focusing on kinesin-1, a biomolecular motor responsible for vesicular transport within cells by converting the chemical energy of ATP hydrolysis into mechanical energy. Further, he talked about their discovery that external force fluctuations, mimicking intracellular nonthermal fluctuations, can accelerate kinesin motility, providing new insights into the adaptation of kinesin to intracellular environments and the application of non-equilibrium theories to general enzyme acceleration (Ariga et al. 2018; Ariga and Mizuno 2020; Ariga et al. 2021).
Dr. Lee-Wei Yang (National Tsing Hua University, National Center for Theoretical Sciences, Academia Sinica) presented applications of a time-dependent linear response theory to proteins that synergized intrinsic protein dynamics with perturbation forces (Yang et al. 2014; Huang and Yang 2019; Huang et al. 2024). This approach enabled the tracking of atom-specific responses over time as mechanical signals propagated, helping identify crucial allosteric sites within proteins. These sites were essential for understanding protein communication and had significant therapeutic potential. Yang’s research identified novel allosteric sites in proteins, such as ATG4B, and screened FDA-approved drugs for their interaction with these sites, showing promising results for cancer treatment.
Dr. Namiko Mitarai (The Niels Bohr Institute) talked about the issue of how the spatial organization of bacterial communities is strongly affected by mechanical interactions among bacteria and with their environments. The resulting spatiotemporal structure heavily influenced the outcomes of microbial competitions, shaping ecological and evolutionary consequences. She combined experiments and mathematical modeling to unravel the interplay between spatial dynamics and microbial competition. When a bacterial population expanded by growth, access to new territory and nutrients at the expanding front became the determinant of the competition. In (quasi) two-dimensional (2D) expansion, bacterial populations spread across flat surfaces. She and her collaborators found that, despite similar growth rates in liquid culture, cells with larger aspect ratios dominated the front of the expansion during 2D range expansion (van den Berg et al. 2024).
Dr. Stefano Bo (King’s College London) discussed the physical properties of biomolecular condensates based on single-molecule dynamics. Bo’s research focused on the formation and dynamics of biomolecular condensates through phase separation. By analyzing single molecules within these condensates, he explored how phase coexistence and non-equilibrium thermodynamics influenced molecular trajectories. His work provided a deeper understanding of the biological functions of these condensates and how they could be modeled to gain further insights into cellular organization (Bo et al. 2021).
In addition to these invited lectures, there were two pick-up talks.
Dr. Huijuan You (Huazhong University of Science and Technology) discussed single-molecule manipulation on DNA structures, such as oncogene promoter G-quadruplexes (G4s), which are important players in regulating gene expression. Her research used magnetic tweezers to study the folding and unfolding kinetics of G4s in the c-MYC promoter sequence, investigating the effects of various G4-binding ligands. You’s findings highlighted the potential of manipulating G4s’ folding/unfolding kinetics by ligands for precise regulation of promoter G4-associated biological activities (Zhang et al. 2021; Liu et al. 2023).
Dr. Takayuki Torisawa (National Institute of Genetics) talked about the effect of active fluctuations of cytoplasmic actomyosin networks on dynein-driven intracellular transports. His research showed that actomyosin-generated fluctuations could significantly enhance dynein-driven transport speeds. By comparing motor-cargo complex motility in vivo and in vitro, his findings suggested that active fluctuations in the cytoplasm played a crucial role in facilitating intracellular transport (Torisawa et al. 2024).
Author contributions
K. H. and C. L. wrote the main manuscript text.
Data availability
No datasets were generated or analysed during the current study.
Declarations
Competing interests
The authors declare no competing interests.
Footnotes
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References
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Data Availability Statement
No datasets were generated or analysed during the current study.