Interaction between Kazal serine proteinase inhibitor SPIPm2 and viral protein WSV477 reduces the replication of white spot syndrome virus

• Published in: Fish & shellfish immunology 2013-09, Vol.35 (3), p.957-964
• Main Authors: Ponprateep, Sirikwan, Phiwsaiya, Kornsunee, Tassanakajon, Anchalee, Rimphanitchayakit, Vichien
• Format: Article
• Language: English
• Subjects: Animals; Gene Expression Regulation, Viral - physiology; Gene Silencing; Hemocytes - cytology; Hemocytes - metabolism; Kazal-type serine proteinase inhibitor; Penaeidae - cytology; Penaeus monodon; RNA Interference; Serine Proteinase Inhibitors - genetics; Serine Proteinase Inhibitors - metabolism; Two-Hybrid System Techniques; Viral Proteins - genetics; Viral Proteins - metabolism; Virus Replication - physiology; White spot syndrome virus; White spot syndrome virus 1 - physiology; WSV477; Yeast two-hybrid screening
• ISSN: 1050-4648; 1095-9947
• DOI: 10.1016/j.fsi.2013.07.009

White spot syndrome (WSS) is a viral disease caused by white spot syndrome virus (WSSV) which leads to severe mortality in cultured penaeid shrimp. In response to WSSV infection in Penaeus monodon, a Kazal serine proteinase inhibitor SPIPm2, normally stored in the granules of granular and semi-granular hemocytes is up-regulated and found to deter the viral replication. By using yeast two-hybrid screening, we have identified a viral target protein, namely WSV477. Instead of being a proteinase, the WSV477 was reported to be a Cys2/Cys2-type zinc finger regulatory protein having ATP/GTP-binding activity. In vitro pull down assay confirmed the protein–protein interaction between rSPIPm2 and rWSV477. Confocal laser scanning microscopy demonstrated that the SPIPm2 and WSV477 were co-localized in the cytoplasm of shrimp hemocytes. Using RNA interference, the silencing of WSV477 resulted in down-regulated of viral late gene VP28, the same result obtained with SPIPm2. In this instance, the SPIPm2 does not function as proteinase inhibitor but inhibit the regulatory function of WSV477. •The SPIPm2 in the granular and semi-granular hemocytes was increased after WSSV infection.•Yeast two-hybrid screening identified a viral zinc finger regulatory protein WSV477.•The interaction between rSPIPm2 and rWSV477 was confirmed by in vitro pull down assay.•The SPIPm2 and WSV477 were co-localized in the cytoplasm of hemocytes.•Silencing of WSV477 resulted in down-regulated of viral late gene VP28.