Biophysics

Dynamics and Activation of Membrane-Bound B Cell Receptor Assembly

1. Hung N. Do
2. Mingfei Zhao
3. S. Munir Alam
4. S. Gnanakaran

Reviewed by PREreview

Dynamic basis of lipopolysaccharide export by LptB2FGC

1. Marina Dajka
2. Tobias Rath
3. Nina Morgner
4. Benesh Joseph

• Curated by eLife

  eLife assessment

  This study provides an important advance in the molecular understanding of the lipopolysaccharide export mechanism and machinery in bacteria. By using advanced spectroscopy approaches, the experiments provide convincing biophysical support for the dynamic behavior of the multisubunit Lpt transport system. This work has implications for understanding bacterial cell envelope biogenesis and developing drugs that target Gram negative pathogens.

Reviewed by eLife

Single turnover transient state kinetics reveals processive protein unfolding catalyzed by Escherichia coli ClpB

1. Jaskamaljot Kaur Banwait
2. Liana Islam
3. Aaron L Lucius

• Curated by eLife

  eLife assessment

  This valuable study presents the development of a single turnover stopped-flow fluorescence experiment to study the kinetics of substrate unfolding and translocation by the bacterial ClpB disaggregase. Using non-physiological nucleotides to bypass the physiological regulation mechanism of ClpB, the authors convincingly show that the ClpB disaggregase is a processive motor with a slow unfolding step preceding rapid translocation. The results of this analysis are of value for future mechanistic studies on energy-dependent unfolding, degradation, and disaggregation molecular machines.

Reviewed by eLife

Escape problem of magnetotactic bacteria - physiological magnetic field strengths help magnetotactic bacteria navigate in simulated sediments

1. Agnese Codutti
2. Mohammad A. Charsooghi
3. Konrad Marx
4. Elisa Cerdá-Doñate
5. Omar Munoz
6. Paul Zaslansky
7. Vitali Telezki
8. Tom Robinson
9. Damien Faivre
10. Stefan Klumpp

• Curated by eLife

  eLife assessment

  This study presents valuable experimental and numerical results on the motility of a magnetotactic bacterium living in sedimentary environments, particularly in environments of varying magnetic field strengths. The evidence supporting the claims of the authors is solid, although the statistical significance comparing experiments with the numerical work is weak. The study will be of interest to biophysicists interested in bacterial motility.

Reviewed by eLife

Should I stay or should I go? Spatio-temporal dynamics of bacterial biofilms in confined flows

1. Massinissa Benbelkacem
2. Gabriel Ramos
3. Fatima El Garah
4. Yara Abidine
5. Christine Roques
6. Yohan Davit

• Curated by eLife

  eLife assessment

  This important study integrates microfluidic experiments and mathematical modeling to investigate how flow dynamics and biofilm growth and detachment influence each other. Using Pseudomonas aeruginosa as a model organism, the study identifies several key effects and stages in biofilm development, albeit with some weaknesses in clearly defining the setup and some of their interpretations. The comparison between experimental results and theoretical models is convincing, providing a robust analysis of the biofilm's behavior under varying flow conditions. The findings will be helpful for researchers working on biofilms and their applications.

Reviewed by eLife

Robust optogenetic inhibition with red-light-sensitive anion-conducting channelrhodopsins

1. Johannes Oppermann
2. Andrey Rozenberg
3. Thomaz Fabrin
4. Cristian González-Cabrera
5. Rafael Parker
6. Oded Béjà
7. Matthias Prigge
8. Peter Hegemann

• Curated by eLife

  eLife assessment

  This important study describes the discovery and further engineering of a red light-activated, chloride-conducting Channelrhodopsin (ACR) that could be used to inhibit neuronal activity. The evidence for the spectral confirmation and biophysical characterization of MsACR and raACR, and ion selectivity are solid; however, the evidence supporting the use of the tools in vivo is incomplete and missing proper controls. In addition, benchmarking against other inhibitory tools is somewhat missing. With the in vivo part strengthened, this paper would interest neuroscientists seeking more efficient ways to inhibit neuronal activity.

Reviewed by eLife

Distinct Activation Mechanisms of CXCR4 and ACKR3 Revealed by Single-Molecule Analysis of their Conformational Landscapes

1. Christopher T Schafer
2. Raymond F Pauszek
3. Martin Gustavsson
4. Tracy M Handel
5. David P Millar

• Curated by eLife

  eLife assessment

  This manuscript describes the characterization of the conformational dynamics of two chemokine receptors at the single-molecule level using FRET. The authors make a convincing case for attributing the distinct interaction and pharmacology of the two receptors to differences in their conformational energy landscape. These important findings will be of interest to scientists working on activation mechanisms of GPCRs and signal transduction.

Reviewed by eLife

The exchange dynamics of biomolecular condensates

1. Yaojun Zhang
2. Andrew GT Pyo
3. Ross Kliegman
4. Yoyo Jiang
5. Clifford P Brangwynne
6. Howard A Stone
7. Ned S Wingreen

• Curated by eLife

  eLife assessment

  This valuable contribution studies factors that impact molecular exchange between dense and dilute phases of biomolecular condensates through continuum models and coarse-grained simulations. The authors provide convincing evidence that interfacial resistance can cause molecules to bounce off the interface and limit mixing. Results like these can inform how experimental results in the field of biological condensates are interpreted.

Reviewed by eLife

The actin cortex acts as a mechanical memory of morphology in confined migrating cells

1. Yohalie Kalukula
2. Marine Luciano
3. Guillaume Charras
4. David B. Brückner
5. Sylvain Gabriele

Reviewed by preLights

Revealing a hidden conducting state by manipulating the intracellular domains in KV10.1 exposes the coupling between two gating mechanisms

1. Reham Abdelaziz
2. Adam P Tomczak
3. Andreas Neef
4. Luis A Pardo

• Curated by eLife

  eLife assessment

  This valuable study examines the role of the interaction between cytoplasmic N- and C-terminal domains in voltage-dependent gating of Kv10.1 channels. The authors suggest that they have identified a hidden open state in Kv10.1 mutant channels, thus providing a window for observing early conformational transitions associated with channel gating. The evidence supporting the major conclusions is solid, but additional work is required to determine the molecular mechanism underlying the observations in this study. Learning the molecular mechanisms could be significant in understanding the gating mechanisms of the KCNH family and will appeal to biophysicists interested in ion channels and physiologists interested in cancer biology.

Reviewed by eLife