Identification of differential expressed proteins and characterization their mRNA expression in thermally stressed Apostichopus japonicus.

In this study, we present a comparative proteomic analysis of the global protein expression changes in sea cucumber after 7 days exposure at 25°C. Using two-dimensional electrophoresis followed by MALDI-TOF MS/MS, 27 protein spots with significant differences in abundance were identified and characterized. The identified proteins belonged primarily to the following four functional categories: cytoskeletal, material and energy metabolism, calcium homeostasis and extracellular matrix. The mRNA expression levels of 7 differentially expressed proteins were further assessed by qRT-PCR. The expression levels of 6 genes, including collagen, ATP synthase, major yolk protein, ferritin, nectin and protein disulfide isomerase showed significant differences under thermal stress, and among them, only two genes—ATP synthase and major yolk protein—showed consistent levels of protein and mRNA expression. Our results offer insight into the complex changes in protein turnover during higher temperature exposure in sea cucumber.