Graf Isabella R, Frey Erwin
Arnold-Sommerfeld-Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians-Universität München, D-80333 Munich, Germany.
Phys Rev Lett. 2017 Mar 24;118(12):128101. doi: 10.1103/PhysRevLett.118.128101. Epub 2017 Mar 21.
Transport of molecular motors along protein filaments in a half-closed geometry is a common feature of biologically relevant processes in cellular protrusions. Using a lattice-gas model we study how the interplay between active and diffusive transport and mass conservation leads to localized domain walls and tip localization of the motors. We identify a mechanism for task sharing between the active motors (maintaining a gradient) and the diffusive motion (transport to the tip), which ensures that energy consumption is low and motor exchange mostly happens at the tip. These features are attributed to strong nearest-neighbor correlations that lead to a strong reduction of active currents, which we calculate analytically using an exact moment identity, and might prove useful for the understanding of correlations and active transport also in more elaborate systems.
分子马达沿着半封闭几何结构中的蛋白质细丝运输是细胞突起中生物相关过程的一个共同特征。我们使用晶格气体模型研究主动运输与扩散运输以及质量守恒之间的相互作用如何导致局部畴壁和马达的尖端定位。我们确定了一种主动马达（维持梯度）和扩散运动（向尖端运输）之间任务分担的机制，该机制确保能量消耗较低且马达交换大多发生在尖端。这些特征归因于强最近邻相关性，这导致主动电流大幅降低，我们使用精确的矩恒等式对其进行了解析计算，并且这可能也有助于理解更复杂系统中的相关性和主动运输。
