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Tissues rely on supracellular signals to coordinate their cells over a long range. Two such tissue-scale cues are calcium waves and patterns of cell-cell alignment or nematic order. During wound healing, for example, calcium waves propagate across a tissue to guide directed cell migration and reepithelialization. Defects in long-range cell-cell alignment, or nematic orientation, can act to localize morphogenetic events in a tissue. Although these two cues have been considered in isolation, we demonstrate a relationship in epithelial tissue between long-range calcium signaling and the cell’s nematic order: The speed of a wound-induced calcium wave depends on the angle between the wave vector and cell axis, with maximal wave speed occurring perpendicular to the tissue’s orientation.

Lateral transport of membrane proteins is governed by the hydrodynamics of lipid bilayers and their coupling to the surrounding fluids. Protein mobility determines its diffusion rate, which can regulate important cellular functions such as cell signaling, especially when diffusion is the rate limiting process. Classic theories, such as the Saffman–Delbrück (SD) model, established the foundation for understanding protein mobility in membranes. SD theory has since been extended in many ways to understand and model the observations and measurements in living and reconstituted systems.

Molecular scale interactions collectively determine the elastic response of membranes, and all-atom models provide the most chemically accurate representation of molecular scale interactions. However, theoretical considerations and previous coarse-grained simulations suggest that very large al-atom simulations are required to directly observe the continuum regime first described by Canham, Evans, and Helfrich. Here we present an all-atom simulation of dioleyoyl phosphatidylcholine containing 10.330 lipids and approximately 3M atoms.

A repeated pattern in cytoskeletal architecture is the aster, in which a number of F-actin filaments emerge star-shaped from a central node. Aster-based structures occur in cytoplasmic actin, the early stages of the cytokinetic ring in yeast, and in the context of biomimetic materials engineering. In this work, we use computational simulation to show that there is an optimal number of filaments per aster that maximizes rigidity, even at a fixed density of F-actin. This nonlinear dependence holds for both the shear and extensional moduli.

Human cardiac muscle function is regulated by interactions between the thick (myosin) and thin (actin) filaments, driven by conformational changes in myosin coupled to ATP hydrolysis, enabling force generation. During the recovery stroke, myosin undergoes conformational rearrangements that position active site residues for ATP hydrolysis and actin interaction, making it a critical step in the kinetic cycle. Genetic cardiomyopathy–causing mutations within myosin are known to affect ATPase activity of myosin, thereby altering force generation.

Structural organization of cellular membranes and membrane proteins is governed by the hydration water. Distribution of water molecules across lipid bilayers is highly heterogeneous due to the amphiphilic nature of this barrier, consisting of 3-4 nm thick hydrophobic core and a hydrophilic region formed by lipid polar head groups. Hyperfine sublevel correlation (HYSCORE) spectroscopy is capable of selective detection of hyperfine interactions originating from water molecules H-bonded directly to the N‒O• group of the nitroxide.

The generation of an epithelial sheet transforms fruit fly embryos from a single syncytial cell directly into a tissue. During this process, the apical microvillus membrane is pulled between peripherally anchored nuclei in a process known as furrow invagination. Experimental measurements have shown that the furrow invagination velocity undergoes slow-to-fast and fast-to-stalled transitions during the formation of individual cells. The causes of such changes are due to multiple intersecting molecular mechanisms, including dynamics of motor proteins, microtubules, and F-actin.

The activation of transcription factor Max-Like Protein x (MLX) is modulated by competition between active dimerization and inactive association with cytosolic lipid droplets (LDs). However, LD association has been shown to depend on the neutral lipid composition. This work explores the mechanism by which MLX specifically targets LDs rich in triacylglycerol (TG) over those with abundant sterol esters (SE). We compare the association ensembles for a potential minimal targeting sequence, an amphipathic helix-loop-helix hairpin, and the full dimerization and cytoplasmic localization domain (DCD), finding the latter requires larger packing defects and quantifiably alters LD membrane properties.

The ability of single-chain bolalipids (or bolaamphiphiles) to self-assemble into vesicular structures remains poorly characterized. Here, we report the synthesis and self-assembly behavior of a new class of proline-based single-chain lipids, a symmetric bipolar molecule (2Pro-C18:1) and, for comparison, a unipolar analogue (1Pro-C18:1), both bearing an unsaturated C18 hydrocarbon chain. Confocal fluorescence microscopy, encapsulation assays, and fluorescence spectroscopy demonstrate that both amphiphiles form stable vesicles capable of entrapping small molecules.

All eukaryotic cells go though a universal sequence of phases during their division cycle, where the phase timings vary according to cell type and state. Dual-pulse nucleoside labeling (DPNL) is a standard, widely applicable experimental DNA base substituting technique to probe cell cycle kinetics at the population level, including in living organisms. In such an experimental protocol, a key scheduling parameter is the choice of waiting time between the two labeling pulses. Here, we model population cell cycle dynamics as a three-stage Poisson process with an idealized S-phase labeling step, and use a simulation-based look-up procedure to demonstrate that the inter-pulse waiting time can be optimized to maximize the signal-to-noise ratio of inferred cycle parameters – an issue that is especially critical in DPNL experiments with limited cell numbers and replicates.

(Biophysical Journal 125, 868–880; February 3, 2026)