Lee Sung-Eun, Yoo Dong-hun, Son Jino, Cho Kijong
Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu, HI, USA.
Proteomics. 2006 Feb;6(3):945-57. doi: 10.1002/pmic.200401349.
Heavy-metal pollution of aquatic ecosystems is a widespread phenomenon after industrial consumption. Whether aquatic organisms are adapted to the heavy-metal pollutants or not, such environmental stress causes changes in physiological responses. In this study, the aquatic midge, Chironomus riparius Meigen, was used to find changes of expression of proteins in relation to cadmium exposure. Dose-response relationships between cadmium concentrations and mortality of 3rd instar midge larvae were observed and the protein levels were compared using PD-Quest after 2-DE. Comparing the intensity of protein spots, 21 proteins decreased and 18 proteins increased in response to cadmium treatment. With increased proteins, three enzymes such as S-adenosylmethionine decarboxylase, O-methyltransferase, and aspartokinase were involved in the glutathione biosynthesis and a key enzyme regulating fatty acid biosynthesis, oleyl-acyl carrier protein thioesterase was also identified. According to the functional classification of decreased levels of proteins, they were involved in energy production, protein fate, nucleotide biosynthesis, cell division, transport and binding, signal transduction, and fatty acid and phospholipid metabolism in the cell. In addition, phenol hydroxylase, thioesterase, zinc metalloprotease, and aspartate kinase were newly expressed after cadmium exposure at the concentration of the LC(10 )value. Therefore, these proteins seem to be potential biomarkers for cadmium exposure in the aquatic ecosystems.
工业消耗后，水生生态系统的重金属污染是一种普遍现象。无论水生生物是否适应重金属污染物，这种环境压力都会导致生理反应发生变化。在本研究中，利用水生摇蚊（Chironomus riparius Meigen）来探究与镉暴露相关的蛋白质表达变化。观察了镉浓度与三龄摇蚊幼虫死亡率之间的剂量反应关系，并在双向电泳（2-DE）后使用PD-Quest比较蛋白质水平。通过比较蛋白质斑点的强度，发现21种蛋白质表达下降，18种蛋白质表达上升以响应镉处理。在表达上升的蛋白质中，鉴定出三种参与谷胱甘肽生物合成的酶，如S-腺苷甲硫氨酸脱羧酶、O-甲基转移酶和天冬氨酸激酶，还鉴定出一种调节脂肪酸生物合成的关键酶，油酰-酰基载体蛋白硫酯酶。根据表达下降蛋白质的功能分类，它们参与细胞内的能量产生、蛋白质命运、核苷酸生物合成、细胞分裂、转运与结合、信号转导以及脂肪酸和磷脂代谢。此外，在镉暴露达到LC(10)值浓度时，新表达了酚羟化酶、硫酯酶、锌金属蛋白酶和天冬氨酸激酶。因此，这些蛋白质似乎是水生生态系统中镉暴露的潜在生物标志物。
