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Raymond E. Goldstein - One of the best experts on this subject based on the ideXlab platform.
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a physical perspective on Cytoplasmic Streaming
Interface Focus, 2015Co-Authors: Raymond E. Goldstein, Jan-willem Van De MeentAbstract:Organisms show a remarkable range of sizes, yet the dimensions of a single cell rarely exceed 100 µm. While the physical and biological origins of this constraint remain poorly understood, exceptions to this rule give valuable insights. A well-known counterexample is the aquatic plant Chara, whose cells can exceed 10 cm in length and 1 mm in diameter. Two spiralling bands of molecular motors at the cell periphery drive the cellular fluid up and down at speeds up to 100 µm s(-1), motion that has been hypothesized to mitigate the slowness of metabolite transport on these scales and to aid in homeostasis. This is the most organized instance of a broad class of continuous motions known as 'Cytoplasmic Streaming', found in a wide range of eukaryotic organisms-algae, plants, amoebae, nematodes and flies-often in unusually large cells. In this overview of the physics of this phenomenon, we examine the interplay between Streaming, transport and cell size and discuss the possible role of self-organization phenomena in establishing the observed patterns of Streaming.
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a physical perspective on Cytoplasmic Streaming invited
arXiv: Biological Physics, 2015Co-Authors: Raymond E. Goldstein, Jan-willem Van De MeentAbstract:Organisms show a remarkable range of sizes, yet the dimensions of a single cell rarely exceed $100$ $\mu$m. While the physical and biological origins of this constraint remain poorly understood, exceptions to this rule give valuable insights. A well-known counterexample is the aquatic plant $Chara$, whose cells can exceed $10$ cm in length and $1$ mm in diameter. Two spiraling bands of molecular motors at the cell periphery drive the cellular fluid up and down at speeds up to $100$ $\mu$m/s, motion that has been hypothesized to mitigate the slowness of metabolite transport on these scales and to aid in homeostasis. This is the most organized instance of a broad class of continuous motions known as "Cytoplasmic Streaming", found in a wide range of eukaryotic organisms - algae, plants, amoebae, nematodes, and flies - often in unusually large cells. In this overview of the physics of this phenomenon, we examine the interplay between Streaming, transport and cell size, and discuss the possible role of self-organization phenomena in establishing the observed patterns of Streaming.
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Cytoplasmic Streaming in plant cells emerges naturally by microfilament self organization
Proceedings of the National Academy of Sciences of the United States of America, 2013Co-Authors: Francis G Woodhouse, Raymond E. GoldsteinAbstract:Many cells exhibit large-scale active circulation of their entire fluid contents, a process termed Cytoplasmic Streaming. This phenomenon is particularly prevalent in plant cells, often presenting strikingly regimented flow patterns. The driving mechanism in such cells is known: myosin-coated organelles entrain cytoplasm as they process along actin filament bundles fixed at the periphery. Still unknown, however, is the developmental process that constructs the well-ordered actin configurations required for coherent cell-scale flow. Previous experimental works on Streaming regeneration in cells of Characean algae, whose longitudinal flow is perhaps the most regimented of all, hint at an autonomous process of microfilament self-organization driving the formation of Streaming patterns during morphogenesis. Working from first principles, we propose a robust model of Streaming emergence that combines motor dynamics with both microscopic and macroscopic hydrodynamics to explain how several independent processes, each ineffectual on its own, can reinforce to ultimately develop the patterns of Streaming observed in the Characeae and other Streaming species.
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Cytoplasmic Streaming in drosophila melanogaster
Biophysical Journal, 2012Co-Authors: Sujoy Ganguly, Lucy S Williams, Isa Palacios, Raymond E. GoldsteinAbstract:The persistent circulation of the cytoplasm, called Cytoplasmic Streaming, occurs in a variety of eukaryotic cells. One context in which Streaming occurs is during the establishment of Drosophila body axes, when Kinesin-1 transports the axes determinants and drives Cytoplasmic Streaming. Although Kinesin is essential for flows, neither the mechanism by which Kinesin induces Streaming nor the impact of these flows on transport are known. We have succeeded in a precise quantitative measurement of the statistical properties of Streaming by Particle Image Velocimetry. We have combined these measurements with an in vivo study of the cytoplasm rheology, to calculate the energy dissipation due to Streaming. Since Kinesin is required for flows we can relate the energy dissipated to the work done on the fluid by Kinesin and determine the minimum number of motors necessary to drive Streaming. Furthermore we have performed these measurements on mutants that effect Kinesin-1 motor activity and found remarkable agreement between our in vivo measurements and in vitro studies.
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Cytoplasmic Streaming enables the distribution of molecules and vesicles in large plant cells
Protoplasma, 2010Co-Authors: Jeanmarie Verchot-lubicz, Raymond E. GoldsteinAbstract:Recent studies of aquatic and land plants show that similar phenomena determine intracellular transport of organelles and vesicles. This suggests that aspects of cell signaling involved in development and response to external stimuli are conserved across species. The movement of molecular motors along cytoskeletal filaments directly or indirectly entrains the fluid cytosol, driving cyclosis (i.e., Cytoplasmic Streaming) and affecting gradients of molecular species within the cell, with potentially important metabolic implications as a driving force for cell expansion. Research has shown that myosin XI functions in organelle movement driving Cytoplasmic Streaming in aquatic and land plants. Despite the conserved cytoskeletal machinery propelling organelle movement among aquatic and land plants, the velocities of cyclosis in plant cells varies according to cell types, developmental stage of the cell, and plant species. Here, we synthesize recent insights into Cytoplasmic Streaming, molecular gradients, cytoskeletal and membrane dynamics, and expand current cellular models to identify important gaps in current research.
Teruo Shimmen - One of the best experts on this subject based on the ideXlab platform.
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the sliding theory of Cytoplasmic Streaming fifty years of progress
Journal of Plant Research, 2007Co-Authors: Teruo ShimmenAbstract:Fifty years ago, an important paper appeared in Botanical Magazine Tokyo. Kamiya and Kuroda proposed a sliding theory for the mechanism of Cytoplasmic Streaming. This pioneering study laid the basis for elucidation of the molecular mechanism of Cytoplasmic Streaming--the motive force is generated by the sliding of myosin XI associated with organelles along actin filaments, using the hydrolysis energy of ATP. The role of the actin-myosin system in various plant cell functions is becoming evident. The present article reviews progress in studies on Cytoplasmic Streaming over the past 50 years.
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Cytoplasmic Streaming in plants
Current Opinion in Cell Biology, 2004Co-Authors: Teruo Shimmen, Etsuo YokotaAbstract:Plant cells are surrounded by a cell wall composed of polysaccharides and hence can change neither their form nor their position. However, active movement of organelles (Cytoplasmic Streaming or protoplasmic Streaming) is observed in plant cells, and involvement of the actin/myosin system in these processes has been suggested. Successful biochemical and biophysical approaches to studying myosins have extensively promoted the understanding of the molecular mechanism underlying these phenomena.
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membrane control of Cytoplasmic Streaming in characean cells
Journal of Plant Research, 1996Co-Authors: Munehiro Kikuyama, Masashi Tazawa, Yoshito Tominaga, Teruo ShimmenAbstract:When a characean cell generates an action potential, Cytoplasmic Streaming transiently stops and then recovers gradually. Calcium ion is one of the most important factors mediating between membrane excitation and cessation of Cytoplasmic Streaming.
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roles of actin filaments in Cytoplasmic Streaming and organization of transvacuolar strands in root hair cells of hydrocharis
Protoplasma, 1995Co-Authors: Teruo Shimmen, Etsuo Yokota, M Hamatani, Shinya Saito, T Mimura, N Fusetani, H KarakiAbstract:Effects of cytochalasin B and mycalolide-B on Cytoplasmic Streaming, organizations of actin filaments and the transvacuolar strand were studied in root hair cells ofHydrocharis, which shows reverse fountain Streaming. Both toxins inhibited Cytoplasmic Streaming and destroyed the organizations of actin filaments and transvacuolar strands. However, we found a great difference between these toxins with respect to reversibility. The effects of cytochalasin B were reversible but not those of mycalolide B. The present results suggest that actin filaments work as a track of Cytoplasmic Streaming and as a cytoskeleton to maintain the transvacuolar strand. The usefulness of root hair cells ofHydrocharis in studying the dynamic organization of actin filaments of plant is discussed.
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physiological and biochemical aspects of Cytoplasmic Streaming
International Review of Cytology-a Survey of Cell Biology, 1994Co-Authors: Teruo Shimmen, Etsuo YokotaAbstract:Publisher Summary This chapter discusses the physiological and biochemical aspects of Cytoplasmic Streaming. Cytoplasmic Streaming has been reported in various plant species ranging from algae to higher plants and fungi. the motive force for Cytoplasmic Streaming in most plant cells is generated by the actin-myosin system, which is also responsible for generating the motive force in muscle contraction and ameboid movement, etc. Cytoplasmic Streaming may play an important role not only in intracellular transport but also in other cell functions. In characean cells, it may affect photosynthesis by controlling the transport of ions or substrate through the plasma membrane. Also, Cytoplasmic Streaming is responsible for intercellular transport in Characeae and in the stem of some higher plants. The mechanism of Cytoplasmic Streaming is elucidated mostly by experiments using characean cells. It is reasonable to say that the motive force of Cytoplasmic Streaming in other plant cells is also generated by the same mechanism as that in characean cells, that is, the sliding of myosin associated with organelles along actin filaments using ATP energy.
Jan-willem Van De Meent - One of the best experts on this subject based on the ideXlab platform.
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a physical perspective on Cytoplasmic Streaming
Interface Focus, 2015Co-Authors: Raymond E. Goldstein, Jan-willem Van De MeentAbstract:Organisms show a remarkable range of sizes, yet the dimensions of a single cell rarely exceed 100 µm. While the physical and biological origins of this constraint remain poorly understood, exceptions to this rule give valuable insights. A well-known counterexample is the aquatic plant Chara, whose cells can exceed 10 cm in length and 1 mm in diameter. Two spiralling bands of molecular motors at the cell periphery drive the cellular fluid up and down at speeds up to 100 µm s(-1), motion that has been hypothesized to mitigate the slowness of metabolite transport on these scales and to aid in homeostasis. This is the most organized instance of a broad class of continuous motions known as 'Cytoplasmic Streaming', found in a wide range of eukaryotic organisms-algae, plants, amoebae, nematodes and flies-often in unusually large cells. In this overview of the physics of this phenomenon, we examine the interplay between Streaming, transport and cell size and discuss the possible role of self-organization phenomena in establishing the observed patterns of Streaming.
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a physical perspective on Cytoplasmic Streaming invited
arXiv: Biological Physics, 2015Co-Authors: Raymond E. Goldstein, Jan-willem Van De MeentAbstract:Organisms show a remarkable range of sizes, yet the dimensions of a single cell rarely exceed $100$ $\mu$m. While the physical and biological origins of this constraint remain poorly understood, exceptions to this rule give valuable insights. A well-known counterexample is the aquatic plant $Chara$, whose cells can exceed $10$ cm in length and $1$ mm in diameter. Two spiraling bands of molecular motors at the cell periphery drive the cellular fluid up and down at speeds up to $100$ $\mu$m/s, motion that has been hypothesized to mitigate the slowness of metabolite transport on these scales and to aid in homeostasis. This is the most organized instance of a broad class of continuous motions known as "Cytoplasmic Streaming", found in a wide range of eukaryotic organisms - algae, plants, amoebae, nematodes, and flies - often in unusually large cells. In this overview of the physics of this phenomenon, we examine the interplay between Streaming, transport and cell size, and discuss the possible role of self-organization phenomena in establishing the observed patterns of Streaming.
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measurement of Cytoplasmic Streaming in single plant cells by magnetic resonance velocimetry
Journal of Fluid Mechanics, 2010Co-Authors: Jan-willem Van De Meent, Andrew J. Sederman, Lynn F. Gladden, Raymond E. GoldsteinAbstract:In the giant cylindrical cells found in Characean algae, multitudes of the molecular motor myosin transport the cytoplasm along opposing spiralling bands covering the inside of the cell wall, generating a helical shear flow in the large central vacuole. It has been suggested that such flows enhance mixing within the vacuole (van de Meent, Tuval & Goldstein, Phys. Rev. Lett., vol. 101, 2008, paper no. 178102) and thereby play a role in regulating metabolism. For this to occur the membrane that encloses the vacuole, namely the tonoplast, must transmit efficiently the hydrodynamic shear generated in the cytoplasm. Existing measurements of Streaming flows are of insufficient spatial resolution and extent to provide tests of fluid mechanical theories of such flows and information on the shear transmission. Here, using magnetic resonance velocimetry (MRV), we present the first measurements of Cytoplasmic Streaming velocities in single living cells. The spatial variation of the longitudinal velocity field in cross-sections of internodal cells of Chara corallina is obtained with spatial resolution of 16 μm and is shown to be in quantitative agreement with a recent theoretical analysis (Goldstein, Tuval & van de Meent, Proc. Natl. Acad. Sci. USA, vol. 105, 2008, p. 3663) of rotational Cytoplasmic Streaming driven by bidirectional helical forcing in the cytoplasm, with direct shear transmission by the tonoplast. These results highlight the open problem of understanding tonoplast motion induced by Streaming. Moreover, this study suggests the suitability of MRV in the characterization of Streaming flows in a variety of eukaryotic systems and for microfluidic phenomena in general.
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Measurement of Cytoplasmic Streaming in Chara Corallina by Magnetic Resonance Velocimetry
Journal of Fluid Mechanics, 2009Co-Authors: Jan-willem Van De Meent, Andrew J. Sederman, Lynn F. Gladden, Raymond E. GoldsteinAbstract:In aquatic plants such as the Characean algae, the force generation that drives cyclosis is localized within the cytoplasm, yet produces fluid flows throughout the vacuole. For this to occur the tonoplast must transmit hydrodynamic shear efficiently. Here, using magnetic resonance velocimetry, we present the first whole-cell measurements of the cross-sectional longitudinal velocity field in Chara corallina and show that it is in quantitative agreement with a recent theoretical analysis of rotational Cytoplasmic Streaming driven by bidirectional helical forcing in the cytoplasm, with direct shear transmission by the tonoplast.
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nature s microfluidic transporter rotational Cytoplasmic Streaming at high peclet numbers
Physical Review Letters, 2008Co-Authors: Jan-willem Van De Meent, Idan Tuval, Raymond E. GoldsteinAbstract:Cytoplasmic Streaming circulates the contents of large eukaryotic cells, often with complex flow geometries. A largely unanswered question is the significance of these flows for molecular transport and mixing. Motivated by "rotational Streaming" in Characean algae, we solve the advection-diffusion dynamics of flow in a cylinder with bidirectional helical forcing at the wall. A circulatory flow transverse to the cylinder's long axis, akin to Dean vortices at finite Reynolds numbers, arises from the chiral geometry. Strongly enhanced lateral transport and longitudinal homogenization occur if the transverse Peclet number is sufficiently large, with scaling laws arising from boundary layers.
Haruo Sugi - One of the best experts on this subject based on the ideXlab platform.
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mechanism of ultra fast actin myosin sliding producing Cytoplasmic Streaming in giant algal cell studied using the centrifuge microscope
Journal of Material Sciences & Engineering, 2018Co-Authors: Shigeru Chaen, Haruo SugiAbstract:In giant intermodal cells of green algae Chara collaria, Cytoplasmic Streaming is produced by ATP-dependent sliding between myosin heads extending from amorphous Cytoplasmic organelles and actin filament arrays (actin cables) fixed on chloroplast rows. The velocity of Cytoplasmic Streaming is many times faster than the maximum myofilament sliding in skeletal muscle. In this article, we compared steady-state force-velocity (P-V) relations between Cytoplasmic myosin and skeletal and cardiac muscle myosins using the centrifuge microscope, in which myosincoated latex beads were made to slide along the actin cables under various centrifugal forces. In contrast with the hyperbolic P-V relation of actin-myosin sliding in skeletal and cardiac myosins, the P-V relation of Cytoplasmic myosin versus actin cable sliding was a straight line, indicating a very large duty ratio and a very small rate of chemomechanical energy conversion. Possible mechanisms of the ultra-fast actin-myosin sliding are discussed.Highlights• The velocity of Cytoplasmic Streaming, caused by ATP-dependent sliding between Cytoplasmic myosin and actin cables in giant algal cells is many times faster than ATP-dependent actin-myosin sliding in skeletal and cardiac muscles.• The mechanism of ultra-fast actin-myosin sliding was studied using the centrifuge microscope, in which beads coated with Cytoplasmic myosin were made to slide along actin cables under various centrifugal forces serving as loads against Cytoplasmic myosin versus actin cable sliding.• Unlike the hyperbolic force-velocity (P-V) relation of skeletal and cardiac muscle actin-myosin sliding, the P-V relation of Cytoplasmic actin myosin sliding was a straight line irrespective of the force generated by Cytoplasmic myosin.• These results indicate a very large duty ratio and a very small efficiency of chemo-mechanical energy conversion in Cytoplasmic actin-myosin sliding.
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force velocity relationships in actin myosin interactions causing Cytoplasmic Streaming in algal cells
The Journal of Experimental Biology, 2003Co-Authors: Haruo Sugi, Shigeru ChaenAbstract:Cytoplasmic Streaming in giant internodal cells of green algae is caused by ATP-dependent sliding between actin cables fixed on chloroplast rows and Cytoplasmic myosin molecules attached to Cytoplasmic organelles. Its velocity (>/=50 micro m s(-1)) is many times larger than the maximum velocity of actin-myosin sliding in muscle. We studied kinetic properties of actin-myosin sliding causing Cytoplasmic Streaming in internodal cell preparations of Chara corallina, into which polystyrene beads, coated with Cytoplasmic myosin molecules, were introduced. Constant centrifugal forces directed opposite to the bead movement were applied as external loads. The steady-state force-velocity (P-V) curves obtained were nearly straight, irrespective of the maximum isometric force generated by Cytoplasmic myosin molecules, indicating a large duty ratio of Cytoplasmic myosin head. The large velocity of Cytoplasmic Streaming can be accounted for, at least qualitatively, by assuming a mechanically coupled interaction between Cytoplasmic myosin heads as well as a large distance of unitary actin-myosin sliding.
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the force velocity relationship of the atp dependent actin myosin sliding causing Cytoplasmic Streaming in algal cells studied using a centrifuge microscope
The Journal of Experimental Biology, 1995Co-Authors: Shigeru Chaen, J Inoue, Haruo SugiAbstract:When uncoated polystyrene beads suspended in Mg-ATP solution were introduced into the internodal cell of an alga Chara corallina, the beads moved along the actin cables with directions and velocities (30-62 microns s-1) similar to those of native Cytoplasmic Streaming. Bead movement was inhibited both in the absence of ATP and in the presence of CA2+, as with native Cytoplasmic Streaming. These results indicate that bead movement is caused by Cytoplasmic myosin molecules attached to the head surface interacting with actin cables. The steady-state force-velocity relationship of the actin-myosin sliding that produces Cytoplasmic Streaming was determined by applying constant centrifugal forces to the beads moving on the actin cables. The force-velocity curve in the positive load region was nearly straight, and the implications of this shape are discussed in connection with the kinetic properties of the actin-myosin interaction in Cytoplasmic Streaming. It is suggested that the time for which a Cytoplasmic myosin head is detached from actin in one cycle of actin-myosin interaction is very short. The Ca(2+)-induced actin-myosin linkages, responsible for the Ca(2+)-induced stoppage of Cytoplasmic Streaming, were shown to be much stronger than the rigor actin-myosin linkages.
Brian D Slaughter - One of the best experts on this subject based on the ideXlab platform.
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spatiotemporal image correlation spectroscopy reveals arp2 3 complex driven Cytoplasmic Streaming in mouse oocytes maintaining meiotic cortical spindle positioning
Biophysical Journal, 2012Co-Authors: Jay R Unruh, Brian D SlaughterAbstract:We use spatio-temporal correlation methods with transmitted light microscopy to demonstrate a novel pattern of internal-to-cortical circular Cytoplasmic flow in meiosis II mouse oocytes. This flow is responsible for poising the spindle near the cortex for completion of meiosis II and successful oocyte fertilization. We show that this flow is driven by a balance of Arp2/3-complex-induced actin nucleation at the cortex and myosin-II-driven contraction of the cortex. STICS analysis of EGFP-Utrophin-labeled actin fibers shows cortical outflows with velocities consistent with those required to drive the Cytoplasmic Streaming. Inhibition of the Arp2/3-complex with CK-666 reverses this flow and leads to internal movement of the spindle away from the cortex. Interestingly, neither inhibition of actin polymerization, myosin-II contraction, nor microtubule depolymerization resulted in spindle internalization or large changes in Cytoplasmic Streaming. Kymograph analysis of the cortex stained with fluorescent Concavalin A demonstrates cortical contraction that is eliminated upon inhibition of myosin-II. Combined inhibition of myosin and Arp2/3-complex results in elimination of reversed Cytoplasmic Streaming.View Large Image | View Hi-Res Image | Download PowerPoint Slide
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dynamic maintenance of asymmetric meiotic spindle position through arp2 3 complex driven Cytoplasmic Streaming in mouse oocytes
Nature Cell Biology, 2011Co-Authors: Jay R Unruh, Manqi Deng, Brian D Slaughter, Boris RubinsteinAbstract:Mammalian oocyte maturation involves two asymmetric meiotic divisions that require the positioning of the meiotic spindle near the cortical area from which the extrusion of the polar bodies occurs. Li and colleagues show that the nucleating activity of the Arp2/3 complex, localized at the cortical actin cap, induces actin-filament flow away from the complex, creating a Cytoplasmic Streaming that pushes the spindle towards the cortex.
