Biophysics

Enhanced bacterial chemotaxis in confined microchannels occurs at lane widths matching circular swimming radius

1. Caijuan Yue
2. Chi Zhang
3. Rongjing Zhang
4. Junhua Yuan

• Curated by eLife

  eLife Assessment

  This important work examines the effects of side-wall confinement on chemotaxis of swimming bacteria in a shallow microfluidic channel. The authors present convincing experimental evidence, combined with geometric analysis and numerical simulations of simplified models, showing that chemotaxis is enhanced when the distance between the side walls is comparable to the intrinsic radius of chiral circular swimming near open surfaces. This study should be of interest to scientists specializing in bacteria-surface interactions.

Reviewed by eLife

Should I stay or should I go? Spatiotemporal 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 combines microfluidic experiments with mathematical modeling to elucidate the reciprocal interplay between flow dynamics and biofilm growth and detachment. Using Pseudomonas aeruginosa as a model organism, the authors identify several key regimes and stages of biofilm development. Overall, the comparison between experimental observations of biofilm behavior under varying flow conditions and corresponding theoretical predictions forms a compelling understanding of the processes involved in biofilm dynamics. The results will be of interest to researchers studying biofilms and their technological and biological applications.

Reviewed by eLife

Adaptor protein supersaturation drives innate immune signaling and cell fate

1. Alejandro Rodriguez Gama
2. Tayla Miller
3. Shriram Venkatesan
4. Jeffrey J Lange
5. Jianzheng Wu
6. Xiaoqing Song
7. William D Bradford
8. Malcolm Cook
9. Jay R Unruh
10. Randal Halfmann

• Curated by eLife

  eLife Assessment

  This important study investigates the self-assembly activity of all 109 human death-fold domains. The data collected using advanced microscopy and distributed amphifluoric FRET-based flow cytometry methods are compelling to support the "phase change battery" model that explains how signal amplification can occur without ATP consumption. This paper provides new insight into the thermodynamic control of protein phase behaviors within cells and will be of interest to those studying a variety of biological pathways involved in inflammatory responses and various forms of cell death.

Reviewed by eLife

Tau hyperphosphorylation impairs cooperative binding to microtubules and perturbs organelle trafficking in neurons

1. Daniel Beaudet
2. Christopher L Berger
3. Adam G Hendricks

• Curated by eLife

  eLife Assessment

  In their valuable study, Beaudet, Berger and Hendricks provide a mechanistic link between disease-associated tau hyperphosphorylation, loss of cooperative tau envelope formation on microtubules, and dysregulation of axonal transport prior to aggregation. Using complementary in vitro reconstitution and human iPSC-derived neuronal assays with phosphodeficient and phosphomimetic tau constructs targeting 14 disease-relevant sites, the authors convincingly show that phosphorylation state alters tau organization on microtubules and differentially impacts kinesin- and lysosome-based transport. The evidence is solid and well aligned with the conclusions, yet the work could be further strengthened by incorporating additional controls and motor-specific assays to refine the mechanistic depth.

Reviewed by eLife

Multi-barrier unfolding of the double-knotted protein, TrmD–Tm1570, revealed by single-molecule force spectroscopy and molecular dynamics

1. Fernando Bruno da Silva
2. Szymon Niewieczerzal
3. Iwona Lewandowska
4. Mateusz Fortunka
5. Maciej Sikora
6. Laura-Marie Silbermann
7. Katarzyna Tych
8. Joanna I Sulkowska

• Curated by eLife

  eLife Assessment

  This study investigates the folding and unfolding behavior of the doubly knotted protein TrmD-Tm1570, providing insight into the molecular mechanisms underlying protein knotting. The findings reveal multiple unfolding pathways and suggest that the formation of double knots may require chaperone assistance, offering valuable insights into topologically complex proteins. The evidence is convincing, supported by consistent agreement between simulation and experiment, though some aspects of the presentation and experimental scope could be clarified or expanded.

Reviewed by eLife

Insights into substrate binding and utilization by hyaluronan synthase

1. Zachery Stephens
2. Julia Karasinska
3. Jochen Zimmer

• Curated by eLife

  eLife Assessment

  This study addresses a fundamental question in glycobiology by elucidating how a single-site processive enzyme orchestrates the alternating addition of sugars to synthesize complex polysaccharides such as hyaluronan. The findings are compelling, providing a clear mechanistic framework supported by strong experimental validation. Major strengths include the integration of high-resolution structural data with rigorous biochemical analyses, resulting in a well-supported model of hyaluronan assembly.

Reviewed by eLife

Pulsed laser lensing for phase modulation in electron microscopy

1. Daniel X Du
2. Adam C Bartnik
3. Cameron JR Duncan
4. Usama Choudhry
5. Tanya Tabachnik
6. Chaim Sallah
7. Yuki Ogawa
8. Ebrahim Najafi
9. Ding-Shyue Yang
10. Jared M Maxson
11. Anthony WP Fitzpatrick

• Curated by eLife

  eLife Assessment

  This important study introduces a pulsed laser phase plate that generates stable phase contrast in electron microscopy, offering a practical alternative to continuous-wave designs that suffer from optical instabilities and diffraction artifacts. The experimental results demonstrate a controllable and stable electron phase shift, and the evidence supporting the feasibility of this approach for phase-contrast electron microscopy is convincing. Clarifying the agreement between experiment and theory and further elaborating on possible applications would strengthen the manuscript.

Reviewed by eLife

Unraveling the Molecular Mechanisms of ABHD5 Membrane Targeting

1. Amit Kumar
2. Matthew Sanders
3. Huamei Zhang
4. Li Zhou
5. Shahnaz Parveen
6. Miriam C Jensen
7. Thomas JD Jørgensen
8. Christopher V Kelly
9. James G Granneman
10. Yu-ming M Huang

• Curated by eLife

  eLife Assessment

  This study makes a valuable contribution to our understanding of how the lipase regulator ABHD5 may control lipase activity through interactions with lipid droplets and cellular membranes. By combining multiscale molecular dynamics simulations with experimental approaches, the authors provide novel molecular insights into this membrane-protein interaction and present evidence suggesting that the regulatory mechanism depends on protein conformational changes and local membrane remodeling. While much of the evidence supporting the main conclusions is convincing, several aspects of the analysis, interpretation, and discussion remain incomplete. Overall, this work will be of interest to structural and molecular biologists working on lipid metabolism and membrane biophysics.

Reviewed by eLife

Conformational Changes of the ABC Transporter BmrA Depend on Membrane Curvature

1. Alicia Damm
2. Kemil Belhadji
3. Raj Kumar Sadhu
4. Su-Jin Paik
5. Aurélie Di-Cicco
6. John Manzi
7. Michele Castellana
8. Raju Regmi
9. Emmanuel Margeat
10. Maxime Dahan
11. Pierre Sens
12. Daniel Lévy
13. Patricia Bassereau

• Curated by eLife

  eLife Assessment

  This valuable study investigates whether the activity of an ABC transporter, BmrA, can be modulated by mechanical stimuli. The authors develop a single-molecule experimental system to address this question, although aspects of the methodological framework are incomplete. This work also develops a convincing theoretical model to explain the effect of membrane curvature on the conformational transitions observed during the activity cycle of this membrane protein. This study is of interest to the fields of membrane biophysics and membrane transport.

Reviewed by eLife

Invasive cancer cells soften collagen networks and disrupt stress-stiffening via volume exclusion, contractility and adhesion

1. Irène Nagle
2. Margherita Tavasso
3. Ankur D. Bordoloi
4. Iain A.A. Muntz
5. Gijsje H. Koenderink
6. Pouyan E. Boukany

Reviewed by PREreview