Tubulin mediates Portunus trituberculatus reovirus infection

Abstract Reoviruses are widespread and infect a broad range of hosts. To date, no study has been reported on an aquatic reovirus receptor. By using viral overlay protein binding assay (VOPBA), swimming crab Portunus trituberculatus reovirus (SCRV) was found to bind to a protein of approximately 550 kDa. MALDI-TOF MS–MS analysis revealed that the protein shares the closest homology with β-tubulin. Mouse membrane proteins were tested by western blot with antibodies against the SCRV-binding protein and mouse tubulin, and uniform positive bands were obtained. The results indicated that the SCRV-binding protein was tubulin. The interaction between tubulin and SCRV was further confirmed with coimmunoprecipitation. SCRV infection in vitro could be blocked by a tubulin-specific antibody. The role of tubulin as a major cell surface protein has been reported previously. These findings suggest that tubulin mediates SCRV infection and may function as a receptor for SCRV. Statement of relevance Swimming crab reovirus (SCRV) spread widely, caused losses of millions of dollars in crab cultivation industry in China. Up to now, no studies have been reported on reovirus receptor in aquatic organisms. This paper found that tubulin serves as a receptor for SCRV in swimming crab. It proposes a new drug target for preventing or controlling SCRV.