Functional Characteristics And Analysis Of Grass Carp DHX40 During GCRV Infection

DHX40,which stands for DEAH(Asp-Glu-Ala-His)box Polypeptide 40,is a member of the DEx D/H-box family.Like other family members,DHX40 has RNA helicase activity,is widely present in every life domain from fish to humans,and plays a role in many fundamental cellular life activities,including transcription,splicing,mi RNA biosynthesis,translation,and RNA degradation.Therefore,DHX40 can also be hijacked by viruses for their own infection and replication.This study investigated the function of DHX40 in grass carp reovirus(GCRV)infection,the related RLR signaling pathway,and the role and mechanism of host innate immune response in negative regulation.The results showed that DHX40 significantly promoted the proliferation of GCRV and increased the level of virus inclusion body production.At 12 H and 24 H after CIK infection with GCRV under normal physiological conditions,DHX40 was localized in cytoplasm and did not migrate.The overexpression of DHX40 gene also significantly decreased the expression level of RLR signaling pathway related genes.Further analysis showed that DHX40 inhibited the formation of MDA5-MAVS complex by binding to MDA5,thereby inhibiting the MDA5-MAVS pathway.