Collective effects in force generation by multiple cytoskeletal filaments pushing an obstacle

8th STATPHYS-KOLKATA

Aparna, J.S.^1 ; Das, Dipjyoti^2 ; Padinhateeri, Ranjith^3 ; Das, Dibyendu^2

Centre for Research in Nanotechnology and Science, Indian Institute of Technology Bombay, Mumbai

400076, India^1

Department of Physics, Indian Institute of Technology Bombay, Mumbai

400076, India^2

Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai

400076, India^3

关键词: Collective effects;    Cytoskeletal filaments;    Force generation;    Hydrolysis process;    Monomer concentration;    Out of equilibrium;    Random mechanisms;    Single filaments;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/638/1/012012/pdf
DOI  :  10.1088/1742-6596/638/1/012012

来源: IOP

【 摘 要 】

We report here recent findings that multiple cytoskeletal filaments (assumed rigid) pushing an obstacle typically generate more force than just the sum of the forces due to individual ones. This interesting phenomenon, due to the hydrolysis process being out of equilibrium, escaped attention in previous experimental and theoretical literature. We first demonstrate this numerically within a constant force ensemble, for a well known model of cytoskeletal filament dynamics with random mechanism of hydrolysis. Two methods of detecting the departure from additivity of the collective stall force, namely from the force-velocity curve in the growing phase, and from the average collapse time versus force curve in the bounded phase, is discussed. Since experiments have already been done for a similar system of multiple microtubules in a harmonic optical trap, we study the problem theoretically under harmonic force. We show that within the varying harmonic force ensemble too, the mean collective stall force of N filaments is greater than N times the mean stall force due to a single filament; the actual extent of departure is a function of the monomer concentration.