Conformational flexibility driving charge-selective substrate translocation across a bacterial transporter.

Bacterial membrane porins facilitate the translocation of small molecules while restricting large molecules, and this mechanism remains elusive at the molecular level. Here, we investigate the selective uptake of large cyclic sugars across an unusual passive membrane transporter, CymA, comprising a charged zone and a constricting N terminus segment. Using a combination of electrical recordings, protein mutagenesis and molecular dynamics simulations, we establish substrate translocation across CymA governed by the electrostatic pore properties and conformational dynamics of the constriction segment.

Insulin signaling accelerates the anterograde movement of Rab4 vesicles in axons through Klp98A/KIF16B recruitment via Vps34-PI3Kinase.

Rab4 GTPase organizes endosomal sorting essential for maintaining the balance between recycling and degradative pathways. Rab4 localizes to many cargos whose transport in neurons is critical for regulating neurotransmission and neuronal health. Furthermore, elevated Rab4 levels in the CNS are associated with synaptic atrophy and neurodegeneration in and humans, respectively.

Molecular Dialogue During Host Manipulation by the Vascular Wilt Fungus .

Vascular wilt fungi are a group of hemibiotrophic phytopathogens that infect diverse crop plants. These pathogens have adapted to thrive in the nutrient-deprived niche of the plant xylem. Identification and functional characterization of effectors and their role in the establishment of compatibility across multiple hosts, suppression of plant defense, host reprogramming, and interaction with surrounding microbes have been studied mainly in model vascular wilt pathogens and .

Imprinting reversible deformations on a compressed soft rod network.

We present emergent behaviour of storing mechanical deformation in compressed soft cellular materials (a network of soft polymeric rods). Under an applied compressive strain field, the soft cellular material transits from an elastic regime to a 'pseudo-plastic' regime (not to be confused with pseudoplasticity in fluids). In the elastic phase, it is capable of forgetting (or relaxing) any applied indentation once the applied indentation is removed.

EYA protein complex is required for Wntless retrograde trafficking from endosomes to Golgi.

Retrograde transport of WLS (Wntless) from endosomes to trans-Golgi network (TGN) is required for efficient Wnt secretion during development. However, the molecular players connecting endosomes to TGN during WLS trafficking are limited. Here, we identified a role for Eyes Absent (EYA) proteins during retrograde trafficking of WLS to TGN in human cell lines.

Designed Nanoarchitectures of a BiOBr/BiOI Nanosheet Heterojunction Anchored on Dendritic Fibrous Nanosilica as Visible-Light Responsive Photocatalysts.

Heterojunctions, particularly those involving BiOBr/BiOI, have attracted significant attention in the field of photocatalysis due to their remarkable properties. In this study, a unique architecture of BiOBr/BiOI was designed to facilitate the rapid transfer of electrons and holes, effectively mitigating the recombination of electron-hole pairs. Accordingly, the BiOBr/BiOI nanosheet heterojunction was anchored on dendritic fibrous nanosilica (DFNS) by the immobilization of BiO nanodots in DFNS and the subsequent reaction with HBr and then HI vapors at room temperature.

Long-range correlations in elastic moduli and local stresses at the unjamming transition.

We explore the behaviour of spatially heterogeneous elastic moduli as well as the correlations between local moduli in model solids with short-range repulsive potentials. We show through numerical simulations that local elastic moduli exhibit long-range correlations, similar to correlations in the local stresses. Specifically, the correlations in local shear moduli exhibit anisotropic behavior at large lengthscales characterized by pinch-point singularities in Fourier space, displaying a structural pattern akin to shear stress correlations.

Charge-symmetric and -asymmetric fragmentation dynamics of argon dimers in slow Ar8+-Ar2 collisions.

We present an experimental study of multiple-electron capture-induced fragmentation dynamics of Ar2m+ (4 ≤m≤ 7) dimer ions in 4 keV/u Ar8+-Ar2 collisions. The fragment recoil ion pairs and the charge-changing projectiles are coincidentally measured using a double coincidence technique. The branching ratios between the different charge-sharing fragmentation channels show an inherent enhancement of the asymmetric channels.

Tri-coordinated zinc alkyl complexes with ^/ coordination of imino-phosphanamidinate chalcogenide ligands as precursors for efficient hydroboration of nitriles and esters.

A series of tri-coordinated zinc alkyl complexes with the general molecular formula [-{NHIP(Ph)(E)N-Dipp}ZnEt] [R = Dipp (2,6-diisopropylphenyl), E = S (3a), Se (3b) and R = Bu (-butyl), E = S (4a), Se (4b)] bearing imino-phosphanamidinate chalcogenide ligands were prepared in good yields from the reaction between the protic imino-phosphanamidinate chalcogenide ligand [NHIP(Ph)(E)NH-Dipp] [R = Dipp, E = S (1a), Se (1b) and R = Bu, E = S (2a), Se (2b)] and diethylzinc at room temperature. The molecular structures of all the zinc complexes were established by single-crystal X-ray diffraction analysis. In the solid state, all complexes exhibited a distorted trigonal planar geometry around the zinc ion.

Single-Molecule Maps of Membrane Insertion by Amyloid-β Oligomers Predict Their Toxicity.

The interaction of small Amyloid-β (Aβ) oligomers with the lipid membrane is an important component of the pathomechanism of Alzheimer's disease (AD). However, oligomers are heterogeneous in size. How each type of oligomer incorporates into the membrane, and how that relates to their toxicity, is unknown.

Tropical and montane Apis cerana show distinct dance-distance calibration curves.

Social bees have evolved sophisticated communication systems to recruit nestmates to newly found food sources. As foraging ranges can vary from a few hundred meters to several kilometers depending on the environment or season, populations of social bee species living in different climate zones likely show specific adaptations in their recruitment communication. Accordingly, studies in the western honey bee, Apis mellifera, demonstrated that temperate populations exhibit shallower dance-calibration curves compared with tropical populations.

Emergent dynamics due to chemo-hydrodynamic self-interactions in active polymers.

The field of synthetic active matter has, thus far, been led by efforts to create point-like, isolated (yet interacting) self-propelled objects (e.g. colloids, droplets, microrobots) and understanding their collective dynamics.

Increasing the accuracy of exchange parameters reporting on slow dynamics by performing CEST experiments with 'high' B fields.

Over the last decade chemical exchange saturation transfer (CEST) NMR methods have emerged as powerful tools to characterize biomolecular conformational dynamics occurring between a visible major state and 'invisible' minor states. The ability of the CEST experiment to detect these minor states, and provide precise exchange parameters, hinges on using appropriate B field strengths during the saturation period. Typically, a pair of B fields with ω (=2πB) values around the exchange rate k are chosen.

Eight-coordinate mono- and dinuclear Dy(III) complexes containing a rigid equatorial plane and an anisobidentate carboxylate ligand in the axial position: synthesis, structure and magnetism.

A rigid pentadentate chelating ligand (HL) has been utilized to synthesize a series of octacoordinate mononuclear complexes, [Dy(L)(PhPO)(OOCR)] (where R = CH (1), C(CH) (2), CF (3)) and a dinuclear complex, [Dy(L)(PhPO){(OOC)CH}] (4) based on the highly anisotropic Dy(III) ion. All the complexes were structurally characterized by single-crystal X-ray diffraction studies. The complexes were formed by the coordination action of the dianionic pentadentate ligand [L], one phosphine oxide, and carboxylate ligands.

Bound Isoscalar Axial-Vector bcu[over ¯]d[over ¯] Tetraquark T_{bc} from Lattice QCD Using Two-Meson and Diquark-Antidiquark Variational Basis.

We report a lattice QCD study of the heavy-light meson-meson interactions with an explicitly exotic flavor content bcu[over ¯]d[over ¯], isospin I=0, and axial-vector J^{P}=1^{+} quantum numbers in search of possible tetraquark bound states. The calculation is performed at four values of lattice spacing, ranging from ∼0.058 to ∼0.

Cell-size-dependent regulation of Ezrin dictates epithelial resilience to stretch by countering myosin-II-mediated contractility.

The epithelial adaptations to mechanical stress are facilitated by molecular and tissue-scale changes that include the strengthening of junctions, cytoskeletal reorganization, and cell-proliferation-mediated changes in tissue rheology. However, the role of cell size in controlling these properties remains underexplored. Our experiments in the zebrafish embryonic epidermis, guided by theoretical estimations, reveal a link between epithelial mechanics and cell size, demonstrating that an increase in cell size compromises the tissue fracture strength and compliance.

Taming Negative Ion Resonances Using Nonlocal Exchange-Correlation Functionals.

The characterization of negative ion resonances poses a fundamental challenge to density functional methods due to the unbound nature of resonances. To overcome this challenge, we propose one-particle nonlocal exchange-correlation (xc) potentials combining the exact-exchange (EXX) and the random phase approximation (RPA) correlation potentials. The negative ion resonances are identified by perturbing the real Hermitian nonlocal xc potentials using complex absorbing local potentials.

Intermittency in the not-so-smooth elastic turbulence.

Elastic turbulence is the chaotic fluid motion resulting from elastic instabilities due to the addition of polymers in small concentrations at very small Reynolds ( ) numbers. Our direct numerical simulations show that elastic turbulence, though a low phenomenon, has more in common with classical, Newtonian turbulence than previously thought. In particular, we find power-law spectra for kinetic energy E(k) ~ k and polymeric energy E(k) ~ k, independent of the Deborah (De) number.

The Thermodynamic Properties of Fat10ylated Proteins Are Regulated by the Fat10ylation Site.

Degradation of proteins by the proteasome is crucial in regulating their levels in the cell. Post-translational modifications, such as ubiquitylation and Fat10ylation, trigger proteasomal degradation of the substrate proteins. While ubiquitylation regulates multiple cellular pathways, Fat10ylation functions explicitly in the inflammatory response pathway.

Phosphatidic acid-dependent recruitment of microtubule motors to spherical supported lipid bilayers for in vitro motility assays.

Motor proteins transport diverse membrane-bound vesicles along microtubules inside cells. How specific lipids, particularly rare lipids, on the membrane recruit and activate motors is poorly understood. To address this, we prepare spherical supported lipid bilayers (SSLBs) consisting of a latex bead enclosed within a membrane of desired lipid composition.

Design approaches for 3D cell culture and 3D bioprinting platforms.

The natural habitat of most cells consists of complex and disordered 3D microenvironments with spatiotemporally dynamic material properties. However, prevalent methods of culture study cells under poorly biomimetic 2D confinement or homogeneous conditions that often neglect critical topographical cues and mechanical stimuli. It has also become increasingly apparent that cells in a 3D conformation exhibit dramatically altered morphological and phenotypical states.

Turbulent Flows Are Not Uniformly Multifractal.

Understanding turbulence rests delicately on the conflict between Kolmogorov's 1941 theory of nonintermittent, space-filling energy dissipation characterized by a unique scaling exponent and the overwhelming evidence to the contrary of intermittency, multiscaling, and multifractality. Strangely, multifractality is not typically envisioned as a local flow property, variations in which might be clues exposing inroads into the fundamental unsolved issues of anomalous dissipation and finite time blowup. We present a simple construction of local multifractality and find that much of the dissipation field remains surprisingly monofractal à la Kolmogorov.

Matrix stiffening promotes perinuclear clustering of mitochondria.

Mechanical cues from the tissue microenvironment, such as the stiffness of the extracellular matrix, modulate cellular forms and functions. As numerous studies have shown, this modulation depends on the stiffness-dependent remodeling of cytoskeletal elements. In contrast, very little is known about how the intracellular organelles such as mitochondria respond to matrix stiffness and whether their form, function, and localization change accordingly.