Cellular Signalling and Cytoskeletal Function Laboratory, The Francis Crick Institute, Lincoln's Inn Fields Laboratory, 44 Lincoln's Inn Fields, London WC2A 3LY, UK.
Nat Microbiol. 2016 Aug 15;1(10):16141. doi: 10.1038/nmicrobiol.2016.141.
During its egress, vaccinia virus transiently recruits AP-2 and clathrin after fusion with the plasma membrane. This recruitment polarizes the viral protein A36 beneath the virus, enhancing actin polymerization and the spread of infection. We now demonstrate that three NPF motifs in the C-terminus of A36 recruit AP-2 and clathrin by interacting directly with the Epsin15 homology domains of Eps15 and intersectin-1. A36 is the first identified viral NPF motif containing protein shown to interact with endocytic machinery. Vaccinia still induces actin tails in the absence of the A36 NPF motifs. Their loss, however, reduces the cell-to-cell spread of vaccinia. This is due to a significant reduction in virus release from infected cells, as the lack of intersectin-1 recruitment leads to a loss of Cdc42 activation, impairing N-WASP-driven Arp2/3-mediated actin polymerization. Our results suggest that initial A36-mediated virus release plays a more important role than A36-driven super-repulsion in promoting the cell-to-cell spread of vaccinia.
在出芽过程中，痘苗病毒在与质膜融合后会短暂招募衔接蛋白 2 和网格蛋白。这种招募使病毒下的 A36 蛋白发生极化，增强肌动蛋白聚合和感染的传播。我们现在证明，A36 羧基末端的三个 NPF 基序通过与 Eps15 和 intersectin-1 的 Epsin15 同源结构域直接相互作用，募集衔接蛋白 2 和网格蛋白。A36 是第一个被确定的与内吞作用机制相互作用的含有 NPF 基序的病毒蛋白。即使没有 A36 NPF 基序，痘苗病毒仍然可以诱导肌动蛋白尾。然而，它们的缺失会降低痘苗病毒的细胞间传播。这是因为从感染细胞中释放的病毒显著减少，因为缺乏 intersectin-1 的募集会导致 Cdc42 激活的丧失，从而损害 N-WASP 驱动的 Arp2/3 介导的肌动蛋白聚合。我们的结果表明，在促进痘苗病毒的细胞间传播中，最初的 A36 介导的病毒释放比 A36 驱动的超级排斥发挥更重要的作用。
