Evolution and function of heat shock protein 90 in economic shellfish: A review

The phylum Mollusca is one of the most diverse groups, second only to arthropods, whose production through aquaculture and wild capture is increasing due to its nutritional and economic values, especially its protein availability for human consumption. However, the negative influence caused by pathogen infection and environmental challenges has led to low aquaculture productivity and economic losses for shellfish farmers. Heat shock proteins, as molecular chaperones, contribute to the folding of nascent proteins, environmental adaptation, the immune response, etc., and involve in the fundamental importance of these proteins to provide protection and cell homeostasis against a variety of biotic and abiotic stressors. Here, we present a review of the current progress on the characterization and function of heat shock protein 90 (HSP90) in economic shellfish. First, we collected and characterized a total of thirty-one HSP90 genes from gastropods and bivalves, which were further characterized for protein structure, selection pressure and phylogenetic analysis using online websites and software, suggesting that these proteins formed two relatively independent branches of gastropods and bivalves, with typical HSP90 protein family signatures and one positively selected site. On the other hand, the current advances on the functional observation of HSP90 involve in response to abiotic and biotic stressors from several economic shellfish, such as abalones, clams, oysters, scallops and mussels. Taken together, these studies provide more evidence for the future of selective breeding for diseases or adverse environmental resistance in shellfish aquaculture.