Interaction between white spot syndrome virus VP26 and hemocyte membrane of shrimp, Fenneropenaeus chinensis

Hemocyte of shrimp as an important target cell for white spot syndrome virus (WSSV) was an optimal target for the investigation of interactions between WSSV structural proteins and host cells. In this study, hemocyte membrane of Fenneropenaeus chinensis (HmFc) was prepared and labeled with digoxigenin (DIG), then used as a probe to detect the HmFc-binding proteins in WSSV structural proteins by modified virus overlay protein binding assay (VOPBA) technique. A prominent immunoreactive protein band was identified in WSSV structural proteins, which was corresponding to VP 26. Subsequently, in order to investigate the VP26-binding protein in HmFc, VP26 was expressed, purified and labeled with fluorescein isothiocyanate (FITC). Detected by indirect immune fluorescence assay (IIFA), FITC-labeled recombinant VP26 (rVP26) showed binding ability to the shrimp hemocytes. Furthermore, result of VOPBA demonstrated that rVP26 could specifically recognize a protein in HmFc with an apparent molecular weight of 42 kDa, which was identified to be β-actin by mass spectrometric analysis. These results indicate that the interaction between VP26 and β-actin might play an important role in WSSV infection.