Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States.
Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States; Department of Biomedical Engineering, Emory University, Atlanta, Georgia, United States.
J Theor Biol. 2019 Nov 7;480:65-70. doi: 10.1016/j.jtbi.2018.11.022. Epub 2018 Nov 23.
We have recently been exploring the idea that axonal transport velocity is "track and motor limited." That is, microtubule length as well as microtubule-associated obstructions interact with the number of motors attached to a specific cargo to determine average cargo velocities. We assert that "slow" and "fast" transport as they are commonly referred to in the literature are really single- versus multi-motor transport along interrupted and obstructed track. To this end, we have recently developed a cargo-level motor model that appears to readily reproduce fast and slow transport simply by altering the number of motors. In the work presented here, we explore the ramifications of this model across a wide range of cargo sizes and motor-motor interactions. We find that categorization of cargo transport into "slow" and "fast" might be a natural consequence of track and motor limited transport as cargo load versus average velocity distribution produced by this model are clearly bi-modal with a curved (roughly square-root) relationship between number of motors and cargo load being the best at reproducing experimental data.
我们最近一直在探索轴突运输速度是“轨道和马达限制”的观点。也就是说，微管长度以及微管相关的障碍物与附着在特定货物上的马达数量相互作用，决定了货物的平均速度。我们断言，文献中通常所说的“慢”和“快”运输实际上是在中断和受阻的轨道上，单一马达与多马达运输的区别。为此，我们最近开发了一种货物级别的马达模型，通过改变马达的数量，似乎很容易再现快和慢运输。在本文中，我们探讨了该模型在广泛的货物大小和马达-马达相互作用下的影响。我们发现，将货物运输分类为“慢”和“快”可能是轨道和马达限制运输的自然结果，因为该模型产生的货物负载与平均速度分布明显呈双峰分布，马达数量与货物负载之间的关系呈曲线（大致平方根），最能再现实验数据。
