Adal Sabri - Academia.edu (original) (raw)

Papers by Adal Sabri

Research paper thumbnail of Elucidating the emergence of heterogeneous motion in living matter from the micro- to the nanoscale

Proteine die Bewegung und Beweglichkeit der Parasiten stark beeinflusst. Dies ließ Rückschlüsse a... more Proteine die Bewegung und Beweglichkeit der Parasiten stark beeinflusst. Dies ließ Rückschlüsse auf etwaige Veränderungen des Zellskeletts oder des Flagellums zu.

Research paper thumbnail of Sensing the spatial resolution limit of phagocytosis

Biophysical Journal, 2022

Research paper thumbnail of Unravelling the origins of anomalous diffusion: from molecules to migrating storks

Anomalous diffusion or, more generally, anomalous transport, with nonlinear dependence of the mea... more Anomalous diffusion or, more generally, anomalous transport, with nonlinear dependence of the mean-squared displacement on the measurement time, is ubiquitous in nature. It has been observed in processes ranging from microscopic movement of molecules to macroscopic, large-scale paths of migrating birds. Using data from multiple empirical systems, spanning 12 orders of magnitude in length and 8 orders of magnitude in time, we employ a method to detect the individual underlying origins of anomalous diffusion and transport in the data. This method decomposes anomalous transport into three primary effects: long-range correlations ("Joseph effect"), fat-tailed probability density of increments ("Noah effect"), and non-stationarity ("Moses effect"). We show that such a decomposition of real-life data allows to infer nontrivial behavioral predictions, and to resolve open questions in the fields of single particle cell tracking and movement ecology.

Research paper thumbnail of Unravelling the origins of anomalous diffusion: from molecules to migrating storks

Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem, Israel Movement Ecolog... more Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem, Israel Movement Ecology Lab, Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, Faculty of Science, The Hebrew University of Jerusalem, Jerusalem, Israel Departments of Physics and Chemistry, University of Massachusetts Boston, MA 02125, USA Wildlife Space-Use Ecology Lab, Department of Wildland Resources and Ecology Center, Utah State University, Logan, UT 84332, USA Institute of Physics and Astronomy, University of Potsdam, Potsdam 14476, Germany Experimental Physics I, University of Bayreuth, D-95440 Bayreuth, Germany Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309, USA Department of Electrical and Computer Engineering, and School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523, USA

Research paper thumbnail of Elucidating the Origin of Heterogeneous Anomalous Diffusion in the Cytoplasm of Mammalian Cells

Physical Review Letters

Diffusion of tracer particles in the cytoplasm of mammalian cells is often anomalous with a marke... more Diffusion of tracer particles in the cytoplasm of mammalian cells is often anomalous with a marked heterogeneity even within individual particle trajectories. Despite considerable efforts, the mechanisms behind these observations have remained largely elusive. To tackle this problem, we performed extensive single-particle tracking experiments on quantum dots in the cytoplasm of living mammalian cells at varying conditions. Analyses of the trajectories reveal a strong, microtubule-dependent subdiffusion with antipersistent increments and a substantial heterogeneity. Furthermore, particles stochastically switch between different mobility states, most likely due to transient associations with the cytoskeleton-shaken endoplasmic reticulum network. Comparison to simulations highlight that all experimental observations can be fully described by an intermittent fractional Brownian motion, alternating between two states of different mobility.

Research paper thumbnail of Microtubule polyglutamylation is important for regulating cytoskeletal architecture and motility in Trypanosoma brucei

Journal of Cell Science

ABSTRACTThe shape of kinetoplastids, such as Trypanosoma brucei, is precisely defined during the ... more ABSTRACTThe shape of kinetoplastids, such as Trypanosoma brucei, is precisely defined during the stages of the life cycle and governed by a stable subpellicular microtubule cytoskeleton. During the cell cycle and transitions between life cycle stages, this stability has to transiently give way to a dynamic behaviour to enable cell division and morphological rearrangements. How these opposing requirements of the cytoskeleton are regulated is poorly understood. Two possible levels of regulation are activities of cytoskeleton-associated proteins and microtubule post-translational modifications (PTMs). Here, we investigate the functions of two putative tubulin polyglutamylases in T. brucei, TTLL6A and TTLL12B. Depletion of both proteins leads to a reduction in tubulin polyglutamylation in situ and is associated with disintegration of the posterior cell pole, loss of the microtubule plus-end-binding protein EB1 and alterations of microtubule dynamics. We also observe a reduced polyglutam...

Research paper thumbnail of Identifying heterogeneous diffusion states in the cytoplasm by a hidden Markov model

Research paper thumbnail of Elucidating the emergence of heterogeneous motion in living matter from the micro- to the nanoscale

Proteine die Bewegung und Beweglichkeit der Parasiten stark beeinflusst. Dies ließ Rückschlüsse a... more Proteine die Bewegung und Beweglichkeit der Parasiten stark beeinflusst. Dies ließ Rückschlüsse auf etwaige Veränderungen des Zellskeletts oder des Flagellums zu.

Research paper thumbnail of Sensing the spatial resolution limit of phagocytosis

Biophysical Journal, 2022

Research paper thumbnail of Unravelling the origins of anomalous diffusion: from molecules to migrating storks

Anomalous diffusion or, more generally, anomalous transport, with nonlinear dependence of the mea... more Anomalous diffusion or, more generally, anomalous transport, with nonlinear dependence of the mean-squared displacement on the measurement time, is ubiquitous in nature. It has been observed in processes ranging from microscopic movement of molecules to macroscopic, large-scale paths of migrating birds. Using data from multiple empirical systems, spanning 12 orders of magnitude in length and 8 orders of magnitude in time, we employ a method to detect the individual underlying origins of anomalous diffusion and transport in the data. This method decomposes anomalous transport into three primary effects: long-range correlations ("Joseph effect"), fat-tailed probability density of increments ("Noah effect"), and non-stationarity ("Moses effect"). We show that such a decomposition of real-life data allows to infer nontrivial behavioral predictions, and to resolve open questions in the fields of single particle cell tracking and movement ecology.

Research paper thumbnail of Unravelling the origins of anomalous diffusion: from molecules to migrating storks

Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem, Israel Movement Ecolog... more Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem, Israel Movement Ecology Lab, Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, Faculty of Science, The Hebrew University of Jerusalem, Jerusalem, Israel Departments of Physics and Chemistry, University of Massachusetts Boston, MA 02125, USA Wildlife Space-Use Ecology Lab, Department of Wildland Resources and Ecology Center, Utah State University, Logan, UT 84332, USA Institute of Physics and Astronomy, University of Potsdam, Potsdam 14476, Germany Experimental Physics I, University of Bayreuth, D-95440 Bayreuth, Germany Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309, USA Department of Electrical and Computer Engineering, and School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523, USA

Research paper thumbnail of Elucidating the Origin of Heterogeneous Anomalous Diffusion in the Cytoplasm of Mammalian Cells

Physical Review Letters

Diffusion of tracer particles in the cytoplasm of mammalian cells is often anomalous with a marke... more Diffusion of tracer particles in the cytoplasm of mammalian cells is often anomalous with a marked heterogeneity even within individual particle trajectories. Despite considerable efforts, the mechanisms behind these observations have remained largely elusive. To tackle this problem, we performed extensive single-particle tracking experiments on quantum dots in the cytoplasm of living mammalian cells at varying conditions. Analyses of the trajectories reveal a strong, microtubule-dependent subdiffusion with antipersistent increments and a substantial heterogeneity. Furthermore, particles stochastically switch between different mobility states, most likely due to transient associations with the cytoskeleton-shaken endoplasmic reticulum network. Comparison to simulations highlight that all experimental observations can be fully described by an intermittent fractional Brownian motion, alternating between two states of different mobility.

Research paper thumbnail of Microtubule polyglutamylation is important for regulating cytoskeletal architecture and motility in Trypanosoma brucei

Journal of Cell Science

ABSTRACTThe shape of kinetoplastids, such as Trypanosoma brucei, is precisely defined during the ... more ABSTRACTThe shape of kinetoplastids, such as Trypanosoma brucei, is precisely defined during the stages of the life cycle and governed by a stable subpellicular microtubule cytoskeleton. During the cell cycle and transitions between life cycle stages, this stability has to transiently give way to a dynamic behaviour to enable cell division and morphological rearrangements. How these opposing requirements of the cytoskeleton are regulated is poorly understood. Two possible levels of regulation are activities of cytoskeleton-associated proteins and microtubule post-translational modifications (PTMs). Here, we investigate the functions of two putative tubulin polyglutamylases in T. brucei, TTLL6A and TTLL12B. Depletion of both proteins leads to a reduction in tubulin polyglutamylation in situ and is associated with disintegration of the posterior cell pole, loss of the microtubule plus-end-binding protein EB1 and alterations of microtubule dynamics. We also observe a reduced polyglutam...

Research paper thumbnail of Identifying heterogeneous diffusion states in the cytoplasm by a hidden Markov model