Department of Pathology, University of California, San Diego, La Jolla, CA, United States; Department of Neurosciences, University of California, San Diego, La Jolla, CA, United States.
Curr Opin Neurobiol. 2020 Aug;63:87-94. doi: 10.1016/j.conb.2020.03.015. Epub 2020 Apr 30.
Slow axonal transport conveys cytosolic and cytoskeletal proteins into axons and synapses at overall velocities that are several orders of magnitude slower than the fast transport of membranous organelles such as vesicles and mitochondria. The phenomenon of slow transport was characterized by in vivo pulse-chase radiolabeling studies done decades ago, and proposed models emphasized an orderly cargo-movement, with apparent cohesive transport of multiple proteins and subcellular structures along axons over weeks to months. However, visualization of cytosolic and cytoskeletal cargoes in cultured neurons at much higher temporal and spatial resolution has revealed an unexpected diversity in movement - ranging from a diffusion-like biased motion, to intermittent cargo dynamics and unusual polymerization-based transport paradigms. This review provides an updated view of slow axonal transport and explores emergent mechanistic themes in this enigmatic rate-class.
缓慢轴突运输将细胞质和细胞骨架蛋白以比囊泡和线粒体等膜细胞器快速运输慢几个数量级的整体速度输送到轴突和突触。几十年来的体内脉冲追踪放射性标记研究对缓慢运输现象进行了特征描述，所提出的模型强调了有序的货物运动，在数周到数月的时间内，多个蛋白质和亚细胞结构沿着轴突以明显的粘性方式运输。然而，在培养神经元中以更高的时间和空间分辨率可视化细胞质和细胞骨架货物揭示了运动的意想不到的多样性——从类似于扩散的偏向运动，到间歇性货物动力学和不寻常的基于聚合的运输范例。本综述提供了对缓慢轴突运输的最新观点，并探讨了这个神秘的速度类别中出现的机制主题。
