scholarly journals 3P162 Nucleotide turnover rates of bipolar myosin filament during actin filament sliding(11. Molecular motor,Poster)

2013 ◽  
Vol 53 (supplement1-2) ◽  
pp. S238
Author(s):  
Takahiro Maruta ◽  
Shingo Miyazaki ◽  
Takahiro Kobatake ◽  
Shigeru Chaen
Keyword(s):  
Actin Filament ◽  
Molecular Motor ◽  
Myosin Filament ◽  
Turnover Rates

scholarly journals 2P197 The head of myosin class-V motor moves along an actin filament with regular, 〜5.5nm steps(37. Molecular motor (II),Poster Session,Abstract,Meeting Program of EABS & BSJ 2006)

2006 ◽  
Vol 46 (supplement2) ◽  
pp. S345
Author(s):  
Takuya Okada ◽  
Hiroto Tanaka ◽  
Atsuko_Hikikoshi Iwane ◽  
Kazuo Kitamura ◽  
Mitsuo Ikebe ◽  
...  
Keyword(s):  
Actin Filament ◽  
Poster Session ◽  
Molecular Motor ◽  
Class V ◽  
Meeting Program

scholarly journals Nucleotide specificity of the enzymatic and motile activities of dynein, kinesin, and heavy meromyosin.

1991 ◽  
Vol 112 (6) ◽  
pp. 1189-1197 ◽  
Author(s):  
T Shimizu ◽  
K Furusawa ◽  
S Ohashi ◽  
Y Y Toyoshima ◽  
M Okuno ◽  
...  
Keyword(s):  
Motor Proteins ◽  
Molecular Motor ◽  
Bovine Brain ◽  
Turnover Rates ◽  
Heavy Meromyosin ◽  
Substrate Specificities ◽  
Different Types ◽  
Atp Analogues ◽  
Nucleotide Specificity

The substrate specificities of dynein, kinesin, and myosin substrate turnover activity and cytoskeletal filament-driven translocation were examined using 15 ATP analogues. The dyneins were more selective in their substrate utilization than bovine brain kinesin or muscle heavy meromyosin, and even different types of dyneins, such as 14S and 22S dynein from Tetrahymena cilia and the beta-heavy chain-containing particle from the outer-arm dynein of sea urchin flagella, could be distinguished by their substrate specificities. Although bovine brain kinesin and muscle heavy meromyosin both exhibited broad substrate specificities, kinesin-induced microtubule translocation varied over a 50-fold range in speed among the various substrates, whereas heavy meromyosin-induced actin translocation varied only by fourfold. With both kinesin and heavy meromyosin, the relative velocities of filament translocation did not correlate well with the relative filament-activated substrate turnover rates. Furthermore, some ATP analogues that did not support the filament translocation exhibited filament-activated substrate turnover rates. Filament-activated substrate turnover and power production, therefore, appear to become uncoupled with certain substrates. In conclusion, the substrate specificities and coupling to motility are distinct for different types of molecular motor proteins. Such nucleotide "fingerprints" of enzymatic activities of motor proteins may prove useful as a tool for identifying what type of motor is involved in powering a motility-related event that can be reconstituted in vitro.

scholarly journals Mechanical model of muscle contraction 2. Kinematic and dynamic aspects of a myosin II head during the working stroke

2019 ◽  
Author(s):  
S. Louvet
Keyword(s):  
Actin Filament ◽  
Myosin Head ◽  
Myosin Ii ◽  
Tangential Force ◽  
Longitudinal Axis ◽  
Myosin Filament ◽  
Analytical Relationship ◽  
Shortening Velocity ◽  
Fixed Plane ◽  
Algorithmic Optimization

AbstractThe condition of a myosin II head during which force and movement are generated is commonly referred to as Working Stroke (WS). During the WS, the myosin head is mechanically modelled by 3 two by two articulated segments, the motor domain (S1a) strongly fixed to an actin molecule, the lever (S1b) on which a motor moment is exerted, and the rod (S2) pulling the myosin filament (Mfil). When the half-sarcomere (hs) is shortened or lengthened by a few nanometers, it is assumed that the lever of a myosin head in WS state moves in a fixed plane including the longitudinal axis of the actin filament (Afil). As a result, the 5 rigid segments, i.e. Afil, S1a, S1b, S2 and Mfil, follow deterministic and configurable trajectories. The orientation of S1b in the fixed plane is characterized by the angle θ. After deriving the geometric equations singularizing the WS state, we obtain an analytical relationship between the hs shortening velocity (u) and the angular velocity of the lever . The principles of classical mechanics applied to the 3 solids, S1a, S1b and S2, lead to a relationship between the motor moment exerted on the lever (MB) and the tangential force dragging the actin filament (TA). We distinguish θup and θdown, the two boundaries framing the angle θ during the WS, relating to up and down conformations. With the usual data assigned to the cross-bridge elements, a linearization procedure of the relationships between u and , on the one hand, and between MB and TA, on the other hand, is performed. This algorithmic optimization leads to theoretical values of θup and θdown equal to +28° (−28°) and −42° (+42°) respectively with a variability of ±5° in a hs on the right (left), data in accordance with the commonly accepted experimental values for vertebrate muscle fibers.

scholarly journals Unidirectional sliding of myosin filaments along the bundle of F-actin filaments spontaneously formed during superprecipitation.

1985 ◽  
Vol 101 (6) ◽  
pp. 2335-2344 ◽  
Author(s):  
S Higashi-Fujime
Keyword(s):  
Actin Filament ◽  
Actin Filaments ◽  
Room Temperature ◽  
The Other ◽  
Reverse Direction ◽  
Myosin Filament ◽  
Bipolar Structure ◽  
Myosin Filaments ◽  
Direction Of Movement ◽  
Cold Spring

I reported previously (Higashi-Fujime, S., 1982, Cold Spring Harbor Symp. Quant. Biol., 46:69-75) that active movements of fibrils composed of F-actin and myosin filaments occurred after superprecipitation in the presence of ATP at low ionic strengths. When the concentration of MgCl2 in the medium used in the above experiment was raised to 20-26 mM, bundles of F-actin filaments, in addition to large precipitates, were formed spontaneously both during and after superprecipitation. Along these bundles, many myosin filaments were observed to slide unidirectionally and successively through the bundle, from one end to the other. The sliding of myosin filaments continued for approximately 1 h at room temperature at a mean rate of 6.0 micron/s, as long as ATP remained in the medium. By electron microscopy, it was found that most F-actin filaments decorated with heavy meromyosin pointed to the same direction in the bundle. Myosin filaments moved actively not only along the F-actin bundle but also in the medium. Such movement probably occurred along F-actin filaments that did not form the bundle but were dispersed in the medium, although dispersed F-actin filaments were not visible under the microscope. In this case, myosin filament could have moved in a reverse direction, changing from one F-actin filament to the other. These results suggested that the direction of movement of myosin filament, which has a bipolar structure and the potentiality to move in both directions, was determined by the polarity of F-actin filament in action.

scholarly journals Local Actin Filament Geometry Dictates How Myosin Va Molecular Motor Teams Transport Liposomes Through 3D Actin Networks in Vitro

2019 ◽  
Vol 116 (3) ◽  
pp. 125a
Author(s):  
Sam Walcott ◽  
Andrew T. Lombardo ◽  
Kathleen M. Trybus ◽  
David M. Warshaw
Keyword(s):  
Actin Filament ◽  
Molecular Motor ◽  
Actin Networks ◽  
Myosin Va

scholarly journals 2P203 Unit step-size in the movement of myosin filament(37. Molecular motor (II),Poster Session,Abstract,Meeting Program of EABS & BSJ 2006)

2006 ◽  
Vol 46 (supplement2) ◽  
pp. S346
Author(s):  
Masatoshi Nishikawa ◽  
Hiroaki Takagi ◽  
So Nishikawa ◽  
Toshio Yanagida
Keyword(s):  
Poster Session ◽  
Molecular Motor ◽  
Myosin Filament ◽  
Step Size ◽  
Meeting Program ◽  
Unit Step

scholarly journals Myosin II filament assemblies in the active lamella of fibroblasts: their morphogenesis and role in the formation of actin filament bundles.

1995 ◽  
Vol 131 (4) ◽  
pp. 989-1002 ◽  
Author(s):  
A B Verkhovsky ◽  
T M Svitkina ◽  
G G Borisy
Keyword(s):  
Electron Microscopy ◽  
Actin Filament ◽  
Mammalian Cells ◽  
Myosin Ii ◽  
Myosin Filament ◽  
Actin Bundles ◽  
Fluorescence And Electron Microscopy ◽  
Myosin Filaments ◽  
Filament Bundles ◽  
Filament Network

The morphogenesis of myosin II structures in active lamella undergoing net protrusion was analyzed by correlative fluorescence and electron microscopy. In rat embryo fibroblasts (REF 52) microinjected with tetramethylrhodamine-myosin II, nascent myosin spots formed close to the active edge during periods of retraction and then elongated into wavy ribbons of uniform width. The spots and ribbons initially behaved as distinct structural entities but subsequently aligned with each other in a sarcomeric-like pattern. Electron microscopy established that the spots and ribbons consisted of bipolar minifilaments associated with each other at their head-containing ends and arranged in a single row in an "open" zig-zag conformation or as a "closed" parallel stack. Ribbons also contacted each other in a nonsarcomeric, network-like arrangement as described previously (Verkhovsky and Borisy, 1993. J. Cell Biol. 123:637-652). Myosin ribbons were particularly pronounced in REF 52 cells, but small ribbons and networks were found also in a range of other mammalian cells. At the edge of the cell, individual spots and open ribbons were associated with relatively disordered actin filaments. Further from the edge, myosin filament alignment increased in parallel with the development of actin bundles. In actin bundles, the actin cross-linking protein, alpha-actinin, was excluded from sites of myosin localization but concentrated in paired sites flanking each myosin ribbon, suggesting that myosin filament association may initiate a pathway for the formation of actin filament bundles. We propose that zig-zag assemblies of myosin II filaments induce the formation of actin bundles by pulling on an actin filament network and that co-alignment of actin and myosin filaments proceeds via folding of myosin II filament assemblies in an accordion-like fashion.

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