Although the precise mechanism by which nonenveloped viruses penetrate biological membranes is unclear, a more coherent understanding of this process is starting to emerge. To initiate membrane penetration, nonenveloped viruses engage host cell factors that impart conformational changes on the viral particles, resulting in the exposure of a hydrophobic moiety or the release of a lytic factor. The viruses' interactions with the limiting membrane subsequently compromise the bilayer integrity. This reaction presumably perforates the bilayer to enable the virus to cross the membrane and reach the cytosol. Valuable insights into this process can be gleaned from the membrane transport mechanisms of enveloped viruses and bacterial toxins. To identify systematically the cellular components that facilitate nonenveloped virus membrane penetration, sensitive assays that monitor the transport event directly must first be established. Moreover, higher-resolution structures of penetration intermediates, particularly those solved in complex with membranes, would provide important molecular details into this process.

中文翻译：

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非包膜病毒渗透到细胞质中。

尽管尚不清楚非包膜病毒穿透生物膜的确切机制，但对这一过程的更加连贯的理解开始出现。为了启动膜渗透，非包膜病毒与宿主细胞因子结合，使宿主颗粒在病毒颗粒上发生构象变化，从而导致疏水部分暴露或溶解因子释放。病毒与限制膜的相互作用随后损害了双层的完整性。据推测，该反应使双层穿孔，使病毒能够穿过膜并到达胞质溶胶。可以从包膜病毒和细菌毒素的膜转运机制中获得对该过程的宝贵见解。为了系统地识别有助于非包膜病毒膜渗透的细胞成分，必须先建立直接​​监测运输事件的敏感测定。此外，渗透中间体的更高分辨率结构，特别是与膜复合的那些，将为该过程提供重要的分子细节。