Cloning of an orange-spotted grouper Epinephelus coioides heat shock protein 90AB (HSP90AB) and characterization of its expression in response to nodavirus

The heat shock proteins (HSPs) family which consists of HSP90, HSP70, and low molecular mass HSPs are involved in chaperone activity. Here, we report the cloning and characterization of HSP90AB gene from orange-spotted grouper, Epinephelus coioides. The full-length of grouper HSP90AB was 727 amino acids and possessed an ATPase domain as well as an evolutionarily conserved molecular chaperone. The HSP90AB-green fluorescent protein fusion protein was evenly distributed in the cytoplasm. Immunohistochemistry (IHC) and real-time polymerase chain reaction (PCR) analyses indicated that the expression of grouper HSP90AB was marginally increased following nodavirus infection. Grouper E. coioides that received HSP90 inhibitor geldanamycin (GA) showed an increase in HSP90AB expression and growth of nodavirus supporting nodavirus replication.