Biophysical Journal

Measuring G protein activation by spectrally resolved imaging fluorescence fluctuation spectroscopy The activation of heterotrimeric G proteins through G-protein-coupled receptors (GPCRs) is a ubiquitous signaling mechanism in eukaryotic biology. The three principal molecular components of this…

Foust & Piston use multicolor fluorescence fluctuation spectroscopy to investigate GPCR–G protein interactions in live cells, finding no stable complexes. Read more to find how their study supports a collision-based model of signal transduction.

Super-Resolution Imaging Reveals PIP2 Nanoscale Clusters in Immune Cells In this study, we used super-resolution microscopy [fluorescence photoactivation localization microscopy (FPALM); Hess, S.T. et al. Biophysical Journal, 2006] to illuminate nanoscale biological struct...

Read about the cover art for the newly released issue of Biophysical Journal on the BPS Blog: www.biophysics.org/blog/super-r...

3D localization of retrovirus assembly in the presence of structured background with deep learning Human immunodeficiency virus type 1 (HIV-1) particle assembly is driven by the Gag structural polyprotein and is a crucial step in the production of new virus particles. Elucidating the details of…

#OPENACCESS: 3D localization of retrovirus assembly in the presence of structured background with deep learning. John Kohler, Kwang-Ho Hur, Elijah Wray, Jesse Donahue, Rayna Addabbo, Louis M. Mansky, and Joachim D. Mueller.

Atomistic modeling of lysophospholipids from the Campylobacter jejuni lipidome Lysophospholipids are an important class of lipids in both prokaryotic and eukaryotic organisms. These lipids typically constitute a very small proportion (<1%) of the bacterial lipidome but can…

#OPENACCESS: Atomistic modeling of lysophospholipids from the Campylobacter jejuni lipidome. Astrid F. Brandner, Kahlan E. Newman, Jonathan W. Essex, and Syma Khalid.

Dynamical properties of chromatin provide insights into key folding principles Even though the three-dimensional static organization of chromatin is highly studied, chromatin is a dynamic structure, and time-dependent changes are crucial for biological function. Although it is…

Imagine chromatin as a tangled origami kite string in a breeze. Kadam et al. tracked how bits of that string jiggle over time and found that loop-extruding motors (like wind gusts) can dominate dynamics even when static folds look controlled by other interactions.

Putting a lid on it: The N-terminal helix of Arf1 inhibits switching via uniform stabilization The Arf and Arf-like GTPases, unlike all other Ras family GTPase members, exhibit a repressed conformation in their inactive, GDP-bound form. An important component of this autoinhibition is their…

The study reveals that the N-terminal helix of Arf1, a GTPase, maintains the protein in the repressed state that is unique to Arf and Arf-like GTPases via overall stabilization of the native state, and no allosteric communication is involved with the switch region.

Special issue call for papers: Viral Biophysics.

Bayesian analysis and efficient algorithms for single-molecule fluorescence data and step counting With the growing adoption of single-molecule fluorescence experiments, there is an increasing demand for efficient statistical methodologies and accurate analysis of the acquired measurements.…

#OPENACCESS: Bayesian analysis and efficient algorithms for single-molecule fluorescence data and step counting. Chiara Mattamira, Alyssa Ward, Sriram Tiruvadi Krishnan, Rajan Lamichhane, Francisco N. Barrera, and Ioannis Sgouralis.

Mapping single-cell rheology of ascidian embryos in the cleavage stages using AFM During early embryo development, cell division is highly organized and synchronized. Understanding the mechanical properties of embryonic cells as a material is crucial in elucidating the physical…

Think of each embryo cell as a jelly-bean with a trampoline skin. Kotani et al. used AFM to press and release and map how “stiff” or “bouncy” each bean is during cleavage. They revealed a mechanical topography of the early embryo all in one map.

Long-range viscosity of the plasma membrane of a living cell measured by a shear-driven flow method The viscosity of the plasma membrane in living cells is a crucial biophysical parameter that regulates cellular functions. We categorize the plasma membrane viscosity into short-range and long-range…

#OPENACCESS: Think the cell membrane flows like a fluid? It depends on scale!
Sakuma et al. measure long-range viscosity in the early C. elegans embryo and find it is four orders of magnitude greater than short-range viscosity, likely due to the actin cytoskeleton.

AlphaFold2 captures conformational transitions in the voltage-gated channel superfamily Voltage-gated cation channels are crucial membrane proteins responsible for the electrical activity in excitable nerve, muscle, and cardiac tissue. These channels respond to changes in the membrane…

An attempt to sample diverse conformations of the voltage-gated channel superfamily via AlphaFold2 predicts activated, deactivated, and intermediate states, and it also shows that the prediction of coupled conformational changes across functional domains is limited.

Special issue call for papers: Modeling Biology at Multiple Scales: From Macromolecules to Cells, Dedicated to Jie Liang.

Hunting for vesicles and chromosomes under time constraints The remarkable property of microtubules is a stochastic alternation between their growth and shrinkage, termed dynamic instability, which has been shown to be vital in their role in capturing and…

In the New and Notable "Hunting for vesicles and chromosomes under time constraints," Maja Novak highlights the paper "Branching, crosslinking and decentralization of microtubules accelerates intracellular assembly."

Adhesion-regulated dynamics of cells A wide variety of dynamic behaviors of cells are closely associated with the active contraction of the cytoskeleton and the cell-substrate adhesion. By inhibiting cell-substrate adhesion, here we…

Cytoskeletal contractions don’t just power movement. Sun et al. combine live-cell experiments and simulations to show that inhibiting cell-substrate adhesion spontaneously triggers diverse dynamic behaviours – from oscillations to protrusions to spreading.

Advances in ligand-based surface engineering strategies for fine-tuning T cell mechanotransduction toward efficient immunotherapy T cell-based immunotherapy has recently emerged as a promising strategy to treat cancer, requiring the activation of antigen-directed cytotoxicity to eliminate cancer cells. Mechanical signaling,…

#OPENACCESS: Advances in ligand-based surface engineering strategies for fine-tuning T cell mechanotransduction toward efficient immunotherapy. Ngoc Luu, Junru Liao, Yifei Fang, and Weiqiang Chen.

Vortex Flow Pattern Reveals the Membrane Viscosity of a Living Cell The membrane viscosity of a cell plays a crucial role in membrane transport and cellular functions. Until now, viscosity measurements have largely relied on lipid model membranes—artificial systems co...

Read about the cover art for the newly released issue of Biophysical Journal on the BPS Blog: www.biophysics.org/blog/vortex-...

The role of hydrophobic collapse in cytotoxic and functional amyloid oligomerization “Amyloid” refers to an insoluble, highly organized protein fibril composed of intermolecular β sheets, known as a cross-β motif. Amyloidogenic proteins are generally driven to aggregate into tightly…

#OPENACCESS: Through MD simulations of β-endorphin31 and amyloid-β42 peptides, the authors demonstrate that maintaining a collapsed state is essential for aberrant oligomerization, underscoring the role of hydrophobic sequences in stabilizing aggregate structures.

Spatially bound functional heterogeneity drives modular organization in β-cell networks Coordinated responses of pancreatic β-cell networks to changes in extracellular nutrient concentrations are a well-established phenomenon with significant implications for insulin secretion. This…

#OPENACCESS: β-cell networks act like neighborhoods with quirky shops—each spot has its specialty, and together they form a modular city! Maja Duh et al. 2025 reveal how spatially bound heterogeneity organizes insulin-secreting communities.

Special issue call for papers: Martin Karplus: In Memoriam.

PIP2 regulation of TRPV4 channels: Binding sites and dynamic coupling Transient Receptor Potential subfamily V4 (TRPV4) is a nonselective cation channel that plays important roles in thermo-sensing, osmoregulation, nociception, and bone homeostasis. The activities of…

Combining structural analysis, docking, and atomistic simulations, this new study identifies a dynamic membrane-facing groove as a potential PIP2 binding site on TRPV4, disputing earlier claims of other proposed binding sites.

Geometry effects on protein mobility in a synapse It is generally assumed that synaptic function requires a tight regulation of the mobility and localization of synaptic proteins. Evidence for this hypothesis has been difficult to gather. Protein…

#OPENACCESS: Protein motion in a synapse is like cars in a roundabout—geometry dictates the traffic flow! Simon Dannenberg et al. 2025 show how shape sculpts protein mobility at these tiny junctions.

Special issue call for papers: Viral Biophysics.

Call for Applications: Editor-in-Chief of Biophysical Journal The Biophysical Society is seeking the next Editor-in-Chief of the Society’s flagship publication, Biophysical Journal. This appointment will begin January 1, 2027, for one five-year term. The missio...

Biophysical Journal seeks candidates to be its next Editor-in-Chief beginning in 2027. Applications and nominations will be accepted until March 1. More information is available at www.biophysics.org/blog/call-for-applications-editor-in-chief-of-biophysical-journal.

The lateral stress profile of fluid lipid membranes as revealed by the diffuse interface approach The distribution of lateral stress within a lipid bilayer is of fundamental biological interest as it regulates membrane-protein interactions, with a particular impact on mechanosensitive channels.…

#OPENACCESS: The lateral stress profile of fluid lipid membranes as revealed by the diffuse interface approach. Matteo Bottacchiari, Mirko Gallo, Marco Bussoletti, and Carlo Massimo Casciola.

Lorenzetti et al. present HiFRAP, an ImageJ/Python tool that extracts kinetic parameters from noisy or imperfect FRAP data, without requiring knowledge of the initial bleach profile. buff.ly/NV1luOp

Special issue call for papers: Modeling Biology at Multiple Scales: From Macromolecules to Cells, Dedicated to Jie Liang.

Ciliary wavelength has its limits Motile cilia are microscopic cellular appendages that beat in fluid to clear mucus from our airways, circulate cerebrospinal fluid in our brains, and determine the left-right asymmetry of our organs…

In the New and Notable "Ciliary wavelength has its limits ," Louis G. Woodhams highlights the paper "The wavelength of the ciliary beat in Chlamydomonas saturates at long ciliary lengths ."

Special issue call for papers: Retinal Proteins: Experiment and Computation.

Special issue call for papers: Martin Karplus: In Memoriam.

The wavelength of the ciliary beat in Chlamydomonas saturates at long ciliary lengths Cilia and flagella support bending waves that propagate along their lengths. In short cilia, such as those of the motile biflagellate green alga Chlamydomonas reinhardtii, the wavelength of the…

#OPENACCESS: Ciliary waves in Chlamydomonas are like dance moves on a packed floor—once the cilia grow too long, the groove maxes out! Elijah H. Lee et al. 2025 show the beat wavelength saturates at extended lengths.