African Swine Fever Virus Protein E199L Promotes Cell Autophagy through the Interaction of PYCR2

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 E199 L protein induced a complete autophagy process in Vero and HEK-293 T cells.Through co-immunoprecipitation coupled with mass spectrometry(Co IP-MS)analysis,we firstly identified that E199 L interact with PYCR2 in vitro.Importantly,our work provides evidence that E199 L down-regulated the expression of PYCR2,resulting in autophagy activation.Overall,our results demonstrate that ASFV E199 L 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.