Rab1A belongs to the small Rab GTPase family and is involved in the lifecycle of numerous viruses. Here, knockdown of Rab1A inhibited CSFV growth. Further study revealed that Rab1A depletion decreased intracellular and extracellular CSFV titers, but did not affect intracellular virus genome copies and E2 protein expression within a virus lifecycle, which suggested that Rab1A is required for CSFV particle assembly rather than for genome replication or virion release. This was proofed by blocking the spread of virus using neutralizing antibodies, through which the negative effects of Rab1A knockdown on multi-cycle replication of CSFV were eliminated. Moreover, co-immunoprecipitation and confocal microscopy assays showed that Rab1A bound to CSFV NS5A protein, indicating that Rab1A and viral NS5A proteins may work cooperatively during CSFV particle assembly. In conclusion, this study demonstrated for the first time that Rab1A is required for CSFV particle assembly and binds to viral particle assembly-related NS5A protein.

Rab1A属于小型Rab GTPase家族，参与众多病毒的生命周期。在这里，Rab1A的抑制作用抑制了CSFV的生长。进一步的研究表明，Rab1A的消耗减少了细胞内和细胞外CSFV滴度，但并未影响病毒生命周期内细胞内病毒基因组拷贝和E2蛋白表达，这表明Rab1A是CSFV粒子组装而不是基因组复制或病毒体释放所必需的。这可以通过使用中和抗体阻止病毒传播来证明，从而消除了Rab1A敲低对CSFV多周期复制的负面影响。此外，免疫共沉淀和共聚焦显微镜分析表明Rab1A与CSFV NS5A蛋白结合，表明Rab1A和病毒NS5A蛋白可能在CSFV颗粒装配过程中协同工作。总之，这项研究首次证明了Rab1A是CSFV颗粒装配所必需的，并与病毒颗粒装配相关的NS5A蛋白结合。