Erlenkämper Christoph, Johann Denis, Kruse Karsten
Theoretische Physik, Universität des Saarlandes, 66041 Saarbrücken, Germany.
Phys Rev E Stat Nonlin Soft Matter Phys. 2012 Nov;86(5 Pt 1):051906. doi: 10.1103/PhysRevE.86.051906. Epub 2012 Nov 5.
We study a driven lattice gas model for the length dynamics of treadmilling filaments in the presence of molecular motors. A treadmilling filament grows by subunit addition at one end and shrinks by subunit removal at the other. Molecular motors can attach to the filament, move towards the shrinking end, and detach from the filament. We consider motors that are also capable of inducing subunit removal at the shrinking filament end. Stochastic simulations reveal a phase of unimodal length distribution and a phase of unbounded growth. Exploiting a condition on the motor flux, we explore the system's phase diagram. In certain limits we can define random walks that allow us to estimate the full length distribution. The width of steady state distributions decreases with increasing motor activity. Our analysis indicates possible ways that cells can use to regulate the size of cytoskeletal structures such as mitotic spindles by controlling various motor properties.
我们研究了一个驱动晶格气体模型，用于描述在分子马达存在的情况下踏车运动细丝的长度动态变化。一根踏车运动的细丝一端通过亚基添加而生长，另一端则通过亚基去除而收缩。分子马达可以附着在细丝上，朝着收缩端移动，并从细丝上脱离。我们考虑的马达还能够在收缩的细丝末端诱导亚基去除。随机模拟揭示了单峰长度分布阶段和无界生长阶段。利用马达通量的一个条件，我们探索了系统的相图。在某些极限情况下，我们可以定义随机游走，从而能够估计全长分布。稳态分布的宽度随着马达活性的增加而减小。我们的分析指出了细胞通过控制各种马达特性来调节细胞骨架结构（如有丝分裂纺锤体）大小的可能方式。
