Characterization of a novel envelope protein WSV010 of shrimp white spot syndrome virus and its interaction with a major viral structural protein VP24.

White spot syndrome virus is one of the most serious viral pathogens causing huge mortality in shrimp farming. Here we report characterization of WSV010, a novel structural protein identified by our recent shotgun proteomics study. Its ORF contains 294 nucleotides encoding 97 amino acids. Transcription analysis using RT-PCR showed that wsv010 is a late gene. Localization analyses by Western blot and immunoelectron microscopy demonstrated that WSV010 is a viral envelope protein. Furthermore, the pull-down assay revealed that WSV010 could interact with VP24, which is a major envelope protein. Since WSV010 lacks a transmembrane domain, these results suggest that WSV010 may anchor to the envelope through interaction with VP24. Previous studies indicated that VP24 could also interact with VP28 and VP26. Therefore, we propose that VP24 may act as a linker protein to associate these envelope proteins together to form a complex, which may play an important role in viral morphogenesis and viral infection.