Effect of microcystin-LR on protein phosphatase 2A and its function in human amniotic epithelial cells  

作　　者：Jing LIANG Fan LI Ya-li ZHANG Zong-lou GUO Li-hong XU 

机构地区：[1]Department of Biochemistry and Genetics, School of Medicine, Zhejiang University, Hangzhou 310058, China [2]Department of Biosystem Engineering, College of Biosystem Engineering and Food Science, Zhejiang University, Hangzhou 310058, China

出　　处：《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》2011年第12期951-960,共10页浙江大学学报（英文版）B辑（生物医学与生物技术）

基　　金：Project supported by the National Natural Science Foundation of China (Nos. 30771827 and 20777067);the Key Special Program on the S & T of China for the Pollution Control and Treatment of Water Bodies (No. 2008ZX07421-001)

摘　　要：Due to their toxicity,the increased distribution of microcystins(MCs) has become an important worldwide problem.MCs have been recognized as inhibitors of protein phosphatase 2A(PP2A) through their binding to the PP2A catalytic subunit.However,the exact mechanism of MC toxicity has not been elucidated,especially concerning the cellular response and its autoregulation.To further dissect the role of PP2A in MC-induced toxicity,the present study was undertaken to determine the response of PP2A in human amniotic epithelial(FL) cells treated with microcystin-LR(MCLR),one of the MC congeners.The results show that a low-dose treatment of MCLR in FL cells for 6 h induced an increase in PP2A activity,and a high-dose treatment of MCLR for 24 h decreased the activity of PP2A,as expected.The increased mRNA and protein levels of the PP2A C subunit may explain the increased activity of PP2A.Furthermore,MCLR altered microtubule post-translational modifications through PP2A.These results further clarify the underlying mechanism how MCLR affects PP2A and may be helpful for elucidating the complex toxicity of MCLR.Due to their toxicity,the increased distribution of microcystins（MCs） has become an important worldwide problem.MCs have been recognized as inhibitors of protein phosphatase 2A（PP2A） through their binding to the PP2A catalytic subunit.However,the exact mechanism of MC toxicity has not been elucidated,especially concerning the cellular response and its autoregulation.To further dissect the role of PP2A in MC-induced toxicity,the present study was undertaken to determine the response of PP2A in human amniotic epithelial（FL） cells treated with microcystin-LR（MCLR）,one of the MC congeners.The results show that a low-dose treatment of MCLR in FL cells for 6 h induced an increase in PP2A activity,and a high-dose treatment of MCLR for 24 h decreased the activity of PP2A,as expected.The increased mRNA and protein levels of the PP2A C subunit may explain the increased activity of PP2A.Furthermore,MCLR altered microtubule post-translational modifications through PP2A.These results further clarify the underlying mechanism how MCLR affects PP2A and may be helpful for elucidating the complex toxicity of MCLR.

关 键 词：MICROCYSTIN-LR Protein phosphatase 2A Phosphatase activity HORMESIS TUBULIN B55α 

分 类 号：Q26[生物学—细胞生物学]