Comparative proteomic analysis of Fujian oyster (Crassostrea angulata) with different cadmium accumulation capabilities

Abstract

Cadmium (Cd) can be transmitted by the food chain and biomagnification, leading serious health risks to humans. It is a major metal pollutant in marine environments. Oysters, being the most widely farmed shellfish globally, have an exceptional ability to accumulate and tolerate Cd. Research has shown that there are significant individual differences in the ability of oysters to accumulate Cd, although their potential molecular basis and key regulatory mechanisms are still unclear. This study utilized 4D-label-free quantitative proteomics to compare individuals within the same Fujian oyster population exhibiting significant difference in Cd accumulation (2–5 times higher or lower Cd levels). It identified 946 differentially expressed proteins (DEPs) totally. Calcium-binding proteins such as calmodulin (CaM) and phospholipid-transporting ATPase ABCA1 were significantly upregulated in high-accumulating oysters, likely providing more cellular binding sites for Cd and enhancing its sequestration, thereby increasing Cd accumulation in oyster tissues. Glutathione S-transferases (GSTs) and heat shock 70 kDa protein 12A (Hspa12a) play key roles in Cd detoxification and cellular antioxidant defense, particularly in oysters with low Cd accumulation. Thus, the varying expression of proteins related to Cd sequestration and detoxification is a crucial factor underlying the variability in Cd accumulation capacity among Fujian oysters. This study illuminates how oysters exhibit differential Cd accumulation at a molecular level. Monitoring marine environmental pollution and guaranteeing the safety of seafood will likewise be crucial.