College of Animal Science, South China Agricultural University & Lingnan Guangdong Laboratory of Modern Agriculture & Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, Guangzhou, 510642, China.
South China Collaborative Innovation Center for Poultry Disease Control and Product Safety, Guangzhou, 510642, China.
Virol Sin. 2021 Apr;36(2):196-206. doi: 10.1007/s12250-021-00375-x. Epub 2021 Apr 8.
African swine fever virus (ASFV), as a member of the large DNA viruses, may regulate autophagy and apoptosis by inhibiting programmed cell death. However, the function of ASFV proteins has not been fully elucidated, especially the role of autophagy in ASFV infection. One of three Pyrroline-5-carboxylate reductases (PYCR), is primarily involved in conversion of glutamate to proline. Previous studies have shown that depletion of PYCR2 was related to the induction of autophagy. In the present study, we found for the first time that ASFV E199L protein induced a complete autophagy process in Vero and HEK-293T cells. Through co-immunoprecipitation coupled with mass spectrometry (CoIP-MS) analysis, we firstly identified that E199L interact with PYCR2 in vitro. Importantly, our work provides evidence that E199L down-regulated the expression of PYCR2, resulting in autophagy activation. Overall, our results demonstrate that ASFV E199L protein induces complete autophagy through interaction with PYCR2 and down-regulate the expression level of PYCR2, which provide a valuable reference for the role of autophagy during ASFV infection and contribute to the functional clues of PYCR2.
非洲猪瘟病毒（ASFV）作为大型 DNA 病毒的一员，可能通过抑制细胞程序性死亡来调节自噬和细胞凋亡。然而，ASFV 蛋白的功能尚未完全阐明，特别是自噬在 ASFV 感染中的作用。三个吡咯啉-5-羧酸还原酶（PYCR）之一，主要参与谷氨酸向脯氨酸的转化。先前的研究表明，PYCR2 的耗竭与自噬的诱导有关。在本研究中，我们首次发现 ASFV E199L 蛋白在 Vero 和 HEK-293T 细胞中诱导完整的自噬过程。通过免疫共沉淀结合质谱分析（CoIP-MS），我们首次鉴定出 E199L 在体外与 PYCR2 相互作用。重要的是，我们的工作提供了证据表明 E199L 下调了 PYCR2 的表达，导致自噬的激活。总的来说，我们的研究结果表明，ASFV E199L 蛋白通过与 PYCR2 相互作用诱导完整的自噬，并下调 PYCR2 的表达水平，为自噬在 ASFV 感染中的作用提供了有价值的参考，并为 PYCR2 的功能线索做出了贡献。
