A5040430789- Cellular Mechanics and Interactions
- Advanced Fluorescence Microscopy Techniques
- Force Microscopy Techniques and Applications
- Cellular transport and secretion
- Nonlinear Dynamics and Pattern Formation
- 3D Printing in Biomedical Research
- Microtubule and mitosis dynamics
- Pickering emulsions and particle stabilization
- Cardiomyopathy and Myosin Studies
- Fungal and yeast genetics research
- Surfactants and Colloidal Systems
- Micro and Nano Robotics
- Proteins in Food Systems
- Diffusion and Search Dynamics
- Material Dynamics and Properties
- Minerals Flotation and Separation Techniques
- Plant Reproductive Biology
- Photosynthetic Processes and Mechanisms
- Ion channel regulation and function
- Metamaterials and Metasurfaces Applications
- Coagulation and Flocculation Studies
- Iron oxide chemistry and applications
- Lipid Membrane Structure and Behavior
- thermodynamics and calorimetric analyses
- Erythrocyte Function and Pathophysiology
Lehigh University
2019-2024
North Carolina State University
2016-2017
Janus and patchy particles are emerging as models for studying complex directed assembly patterns precursors of new structured materials composites. Here we show how lipid-induced capillary bridging could serve a nonconventional method assembling into ordered structures. Iron oxide surface patches on latex microspheres were selectively wetted with liquid lipid, driving the particle two- three-dimensional clusters via interparticle bridge formation. The phase bridges allows local...
Class I myosins (myosin-Is) colocalize with Arp2/3 complex–nucleated actin networks at sites of membrane protrusion and invagination, but the mechanisms by which myosin-I motor activity coordinates branched assembly to generate force are unknown. We mimicked interplay these proteins using “comet tail” bead motility assay, where nucleated complex on surface beads coated nucleation-promoting factor. observed that increased movement efficiency thinning without affecting growth rates. Myosin-I...
Cells self-organize using reaction-diffusion and fluid-flow principles. Whether bulk membrane flows contribute to cell patterning has not been established. Here, mathematical modeling, optogenetics, synthetic probes, we show that polarized exocytosis causes lateral away from regions of insertion. Plasma membrane–associated proteins with sufficiently low diffusion and/or detachment rates couple the deplete areas exocytosis. In rod-shaped fission yeast cells, zones Cdc42 GTPase activity...
Force transmission at integrin-based adhesions is important for cell migration and mechanosensing. Talin an essential focal adhesion (FA) protein that links F-actin to integrins. constantly moves on FAs, yet how simultaneously maintains the connection transmits forces integrins remains unclear. Here we show a critical role of dynamic unfolding in force transmission. Using single-molecule speckle microscopy, found majority are bound only either or substrate, whereas 4.1% linked both...
A key factor of actin cytoskeleton organization in cells is the interplay between dynamical properties filaments and cell geometry, which restricts, confines directs their orientation. Crosslinking interactions among filaments, together with geometrical cues regulatory proteins can give rise to contractile rings dividing neurons. Motivated by recent vitro experiments, this work we performed computer simulations study basic aspects confinement attractive filaments. We used a spring-bead model...
Mechanical forces, actin filament turnover, and adhesion to the extracellular environment regulate lamellipodial protrusions. Computational mathematical models at continuum level have been used investigate molecular clutch mechanism, calculating stress profile through lamellipodium around focal adhesions. However, forces deformations of individual filaments not considered while interactions between networks bundles is easily accounted with such methods. We develop a filament-level model...
Abstract Cell mechano-sensation and adaptation are supported by the actin network. The microtubule network is not considered to be directly sensitive mechanical forces acting on a cell. However, recent studies isolated microtubules in vitro have shown that bending an impact their structure, composition lifespan, suggesting that, cellular context, may react forces. We tested this hypothesis living cells subjecting them cycles of compressive found became distorted, less dynamic more stable....
Local Cdc42 GTPase activation promotes polarized exocytosis, resulting in membrane flows that deplete low-mobility membrane-associated proteins from the growth region. To investigate self-organizing properties of secretion-polarization system under flow, we developed a reaction-diffusion particle model. The model includes positive feedback Cdc42, hydrolysis by GTPase-activating (GAPs), and flow-induced displacement exo/endocytosis. Simulations show how polarization relies on depletion low...
Colloids with anisotropic shape and charge distribution can assemble into a variety of structures that could find use as novel materials for optical, photonic, electronic structural applications. Because experimental characterization the many possible types multi-shape multipolar colloidal particles form useful is difficult, search be enhanced by simulations particle assembly. We have simulated system dipolar rods at fixed aspect ratio using discontinuous molecular dynamics (DMD) to...
A major research theme in materials science is determining how the self-assembly of new generations colloidal particles complex shape and surface charge guided by their interparticle interactions. In this paper, we describe results from quasi-2D Monte Carlo simulations systems with offset transversely-oriented extended dipole-like distributions interacting via an intermediate-ranged Yukawa potential. The are cooled slowly through annealing procedure during which temperature lowered discrete...
Cells polarize for growth, motion, or mating through regulation of membrane-bound small GTPases between active GTP-bound and inactive GDP-bound forms. Activators (GEFs, GTP exchange factors) inhibitors (GAPs, GTPase activating proteins) provide positive negative feedbacks. We show that a reaction–diffusion model on curved surface accounts key features polarization organism fission yeast. The implements Cdc42 membrane diffusion using measured values coefficients dissociation rates assumes...
Myosin-Is colocalize with Arp2/3 complex-nucleated actin networks at sites of membrane protrusion and invagination, but the mechanisms by which myosin-I motor activity coordinates branched assembly to generate force are unknown. We mimicked interplay these proteins using "comet tail" bead motility assay, where nucleated complex on surface beads coated WCA domain N-WASP. observed that increased movement efficiency thinning without affecting growth rates. Remarkably, triggered symmetry...
Summary Robust coordination of surface and volume changes is critical for cell integrity. Few studies have elucidated the plasma membrane (PM) remodeling events during alteration, especially regarding PM sensing its subsequent rearrangements. Here, using fission yeast protoplasts, we reveal a Ca 2+ -dependent mechanism addition that ensures integrity allows expansion acute hypoosmotic swelling. We show MscS-like mechanosensitive channels activated by tension control extracellular influx,...
Abstract Cells self-organize using reaction-diffusion and fluid-flow principles. Whether bulk membrane flows contribute to cell patterning has not been established. Here, mathematical modelling, optogenetics synthetic probes, we show that polarized exocytosis causes lateral away from regions of insertion. Plasma membrane-associated proteins with sufficiently low diffusion and/or detachment rates couple the deplete areas exocytosis. In rod-shaped fission yeast cells, zones Cdc42 GTPase...
Abstract Force transmission at integrin-based adhesions is important for cell migration and mechanosensing. Talin an essential focal adhesion (FA) protein that links F-actin to integrins. constantly moves on FAs, yet how simultaneously maintains the connection transmits forces integrins remains unclear. Here we show a critical role of dynamic unfolding in force transmission. Using single-molecule speckle microscopy, found majority are bound only either or substrate, whereas 4.1% linked both...
We have performed Monte Carlo (MC) simulations on two-dimensional systems of quadrupole particles confined to a triangular lattice in order determine the conditions that permit formation limit-periodic phase. found structures form only when rotations are set six orientations aligned with directions. Related including striped and unidirectional rattler phases π/π66 or continuous allowed. Order parameters signaling structure related measured as function temperature. Our findings elucidate...
Abstract A key factor of actin cytoskeleton organization in cells is the interplay between dynamical properties filaments and cell geometry, which restricts, confines directs their orientation. Crosslinking interactions among filaments, together with geometrical cues regulatory proteins can give rise to contractile rings dividing neurons. Motivated by recent vitro experiments, this work we performed computer simulations study basic aspects confinement attractive filaments. We used a...
Abstract Mechanical forces, actin filament turnover, and adhesion to the extracellular environment regulate lamellipodial protrusions. Computational mathematical models at continuum level have been used investigate molecular clutch mechanism, calculating stress profile through lamellipodium around focal adhesions. However, forces deformations of individual filaments not considered while interactions between networks bundles is easily accounted with such methods. We develop a filament-level...