Deficient of glycosylation site in the envelop protein attenuated Zika virus replication in mosquito cells

The Zika virus (ZIKV) envelope (E) protein is critical for viral replication and host interactions. Although glycosylation of the E protein is known to influence viral infectivity and immune evasion, the specific functional roles of E protein glycosylation in ZIKV infectivity in mosquito cells remain unclear.

In this study, we generated a deglycosylation mutant ZIKV with a T156I substitution in the E protein and investigated its effects on viral replication and viral-host interactions in mosquito C6/36 cells.

Our results demonstrated that the T156I mutant exhibited attenuated replication compared to the wild-type virus during the early stages (0-24 hours) post-virus infection in mosquito C6/36 cells. This attenuation was associated with reduced E protein expression, which was regulated at the post-transcriptional level. RNA sequencing further revealed that the T156I mutation significantly altered virus-host interactions, particularly affecting the extracellular matrix (ECM) signaling pathway. Notably, several genes involved in the ECM signaling pathway, including THBS1, ITGAL, IL-1A, and CXCL8, were found to inhibit the T156I mutant but not the wild-type ZIKV. Structural analysis and in silico molecular docking suggested that the T156I mutation impaired the stability of the E protein dimer rather than its interactions with neutralizing antibodies.

Collectively, these findings provide novel insights into the role of E protein glycosylation in ZIKV infection, and may have significant implications for anti-ZIKV strategies.