Down-regulation of neuropathy target esterase by protein kinase C activation with PMA stimulation.
Neuropathy target esterase (NTE) was originally identified as the primary target site of those organophosphorus compounds that induce delayed neuropathy in human and some animals. Here we examined the role of protein kinase C (PKC) in the regulation of the NTE activity in mammalian cells. Six-hour exposure of human neuroblastoma SK-N-SH cell to a PKC activator phorbol 12-myristate 13-acetate (PMA) decreased the activity of NTE, and this effect was blocked by the PKC inhibitor staurosporine. These results suggest that PKC down-regulates the activity of NTE. NTE protein levels were down-regulated by PMA-stimulation as detected by Western blot analysis using the NTE-specific antibody, which resulted from down-regulation of NTE mRNA level as verified by real-time reverse transcription polymerase chain reaction (RT-PCR). However, there were no changes in the activity or protein levels of stable expression of NTE esterase activity domain (NEST) in SK-N-SH cells and transient expression of full-length NTE construct in COS7 cells driven by cytomegalovirus (CMV) promoter rather than by the cell's own one, despite the absence or presence of PMA stimulation. Together, these findings suggest that stimulation with PMA reduces the expression of NTE mRNA levels but does not affect the exogenous promoter-driven NTE expression in mammalian cells.
Chen
Rui
R
Laboratory of Molecular Toxicology, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 25 Beisihuanxilu Road, Beijing 100080, P.R. China.
Chang
Ping-An
PA
Long
Ding-Xin
DX
Yang
Lin
L
Wu
Yi-Jun
YJ
D000818:Animals; D019556:COS Cells; D002265:Carboxylic Ester Hydrolases / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D015536:Down-Regulation / Q000187:drug effects* / Q000235:genetics*; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D011401:Promoter Regions, Genetic / Q000235:genetics; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D004791:Enzyme Inhibitors; D012333:RNA, Messenger; D011493:Protein Kinase C; D002265:Carboxylic Ester Hydrolases; C021859:neurotoxic esterase; D013755:Tetradecanoylphorbol Acetate