PDF(Pubmed)
Abstract：
Lyssaviruses are well-known worldwide and often cause fatal encephalitis. Previous studies have shown that autophagy is beneficial for the replication of rabies virus (RABV), the representative lyssavirus, but the detailed mechanism remains obscure. In this study, we showed that the rabies virus matrix protein (RABV-M) used its PPxY motif to interact with the E3 ubiquitin-protein ligase NEDD4. NEDD4 then recruited MAP1LC3/LC3 via its LC3-interacting region (LIR). Interestingly, after binding to the ubiquitinated RABV-M, NEDD4 could bind more LC3 and enhance autophagosome accumulation, while NEDD4 knockdown significantly reduced M-induced autophagosome accumulation. Further study revealed that RABV-M prevented autophagosome-lysosome fusion and facilitated viral budding. Inhibition of RABV-M-induced autophagosome accumulation reduced the production of extracellular virus-like particles. We also found that M proteins of most lyssaviruses share the same mechanism to accumulate autophagosome by hijacking NEDD4. Collectively, this study revealed a novel strategy for lyssaviruses to achieve efficient viral replication by exploiting the host autophagy system.Abbreviations: ABLV: Australian bat lyssavirus; ATG5: autophagy related 5; Baf A1:bafilomycin A1;co-IP: co-immunoprecipitation; CQ: chloroquine; DAPI:4\',6-diamidino-2\'-phenylindole; DMSO: dimethyl sulfoxide; EBLV:European bat lyssavirus; GFP: green fluorescent protein; GST:glutathione S-transferase; hpi: hours post-infection; hpt: hourspost-transfection; LIR: LC3-interactingregion;MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; mCherry:red fluorescent protein; MOI: multiplicity of infection; NC: negativecontrol; MVB: multivesicular body; NEDD4: neural precursorcell-expressed developmentally down-regulated 4; RABV: rabies virus;SQSTM1/p62: sequestosome 1; VLP: virus-like particle; VPS4B: vacuolarprotein sorting 4B; TEM: transmission electron microscopy; WB:western blotting; WT: wild-type; μm: micrometer; μM: micromole.
摘要：
镰刀病毒在世界范围内众所周知，通常会导致致命的脑炎。先前的研究表明，自噬有利于狂犬病病毒（RABV）的复制，代表性的Lyssavirus,但是详细的机制仍然不清楚。在这项研究中,我们表明，狂犬病病毒基质蛋白（RABV-M）使用其PPxY基序与E3泛素蛋白连接酶NEDD4相互作用。然后，NEDD4通过其LC3相互作用区（LIR）招募MAP1LC3/LC3。有趣的是,与泛素化的RABV-M结合后，NEDD4可以结合更多的LC3并增强自噬体的积累，而NEDD4敲低显著降低了M诱导的自噬体积累。进一步的研究表明，RABV-M阻止了自噬体-溶酶体融合并促进了病毒出芽。抑制RABV-M诱导的自噬体积累减少了细胞外病毒样颗粒的产生。我们还发现，大多数病毒的M蛋白通过劫持NEDD4积累自噬体具有相同的机制。总的来说，这项研究揭示了lyssavirus通过利用宿主自噬系统实现高效病毒复制的新策略。
