加州大学圣迭戈分校的Elizabeth Villa和Joe Pogliano研究组合作首次报道病毒衣壳能够在细菌中沿着病毒来源的微管纤维进行运输。2019年6月，国际知名学术期刊《细胞》发表了这一成果。

真核细胞的病毒能够利用微管来运输货物，但这样的例子在细菌中没有被报道过。几种大型的假单胞菌噬菌体（细菌病毒）能够组装出一个动态的微管（PhuZ蛋白）纺锤结构，并定位于拟核中复制的DNA中间。

研究人员发现，病毒衣壳在膜上组装完成后会迅速沿着病毒自身来源的PhuZ微管朝噬菌体核移动来包裹DNA。纺锤结构旋转噬菌体核时，衣壳得以围绕在核的表面。PhuZ微管以恒定的速率朝着核区踏车式移动，其速率与衣壳移动以及核旋转的线速度相近。当PhuZ的GTP水解能力缺陷时，微管便保持静止状态，此时病毒衣壳也被陷其中无法移动。因此，这项工作揭示了病毒衣壳通过附着在自己产生的微管上通过PhuZ的极性聚合朝着核区运动的转运和分布机制。该研究首次证明了噬菌体细胞骨架在细菌中进化出货物运输能力。

附：英文原文

Title: Viral Capsid Trafficking along Treadmilling Tubulin Filaments in Bacteria

Author: Vorrapon Chaikeeratisak, Kanika Khanna, Katrina T. Nguyen, David A. Agard, Elizabeth Villa, Joe Pogliano

Issue&Volume: Jun 13, 2019 Volume 177Issue 7 

Abstract: Cargo trafficking along microtubules is exploited by eukaryotic viruses, but no such examples have been reported in bacteria. Several large Pseudomonas phages assemble a dynamic, tubulin-based (PhuZ) spindle that centers replicating phage DNA sequestered within a nucleus-like structure. Here, we show that capsids assemble on the membrane and then move rapidly along PhuZ filaments toward the phage nucleus for DNA packaging. The spindle rotates the phage nucleus, distributing capsids around its surface. PhuZ filaments treadmill toward the nucleus at a constant rate similar to the rate of capsid movement and the linear velocity of nucleus rotation. Capsids become trapped along mutant static PhuZ filaments that are defective in GTP hydrolysis. Our results suggest a transport and distribution mechanism in which capsids attached to the sides of filaments are trafficked to the nucleus by PhuZ polymerization at the poles, demonstrating that the phage cytoskeleton evolved cargo-trafficking capabilities in bacteria.

DOI: https://doi.org/10.1016/j.cell.2019.05.032

Source: https://www.cell.com/cell/fulltext/S0092-8674(19)30560-4