Alteration of the kidney membrane proteome of Mizuhopecten yessoensis induced by low-level methyl parathion exposure.

Methyl parathion (MP) is a widely used organophosphorus pesticide that causes severe health and environmental effects. We investigated the alteration of the proteomic profile in the membrane enriched fraction of the kidneys of the scallop Mizuhopecten yessoensis exposed to low-level MP. Gas chromatography analysis showed that MP residues were significantly accumulated in the kidneys and the digestive glands of the scallops. According to two-dimensional electrophoresis, 17 proteins were differentially modulated under MP exposure. The mRNA expressions of 12 differential proteins were analyzed using quantitative PCR, and 10 showed consistent alteration of mRNA level with that of protein expression level. Altered expressions of two proteins (mitochondrial processing peptidase and α-tubulin) were also examined using Western blotting, showing that the mitochondrial processing peptidase was down-regulated but α-tubulin remained unchanged in response to MP exposure. Subcellular locations of all the identified proteins that were predicted using bioinformatics tools indicate that few of them are permanently located in the membrane. The differentially expressed proteins are involved in several critical biological processes, and their relevance to human health has been illuminated. These data taken together have provided some novel insights into the chronic toxicity mechanism of MP and have suggested mitochondrial processing peptidase as a potential biomarker for human health and environmental monitoring.