Calcium signaling-induced Smad3 nuclear accumulation induces acetylcholinesterase transcription in apoptotic HeLa cells.
Recently, acetylcholinesterase (AChE) has been studied as an important apoptosis regulator. We previously showed that cellular calcium mobilization upregulated AChE expression by modulating promoter activity and mRNA stability. In this study, we have identified a potential Smad3/4 binding element, TGCCAGACA, located within the -601 to -571 bp fragment of the AChE promoter, as an important calcium response motif. Smad2/3 and Smad4 were shown to bind this element. Overexpression of human Smad3 increased AChE transcription activity in a dose-dependent manner in HeLa cells, whereas dominant-negative Smad3 blocked this activation. Upon A23187 and thapsigargin treatment, nuclear Smad3 accumulation was observed, an effect that was blocked by the intracellular Ca(2+) chelator BAPTA-AM. Calcium-induced AChE transcriptional activation was significantly blocked when the nuclear localization signal of Smad3 was destroyed. Taken together, our data suggest Smad3 can regulate AChE transcriptional activation following calcium-induced nuclear accumulation.
Gao
Wei
W
Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 YueYang Road, Shanghai, 200031, China.
Zhu
Hui
H
Zhang
Jing-Ya
JY
Zhang
Xue-Jun
XJ
D000110:Acetylcholinesterase / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000502:physiology*; D002467:Cell Nucleus / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D006367:HeLa Cells; D006801:Humans; D011401:Promoter Regions, Genetic; D051899:Smad2 Protein / Q000378:metabolism; D051900:Smad3 Protein / Q000235:genetics / Q000378:metabolism*; D051901:Smad4 Protein / Q000378:metabolism; D019284:Thapsigargin / Q000378:metabolism; D014158:Transcription, Genetic
D004791:Enzyme Inhibitors; C497782:SMAD2 protein, human; D051899:Smad2 Protein; D051900:Smad3 Protein; D051901:Smad4 Protein; D019284:Thapsigargin; D000110:Acetylcholinesterase; D002118:Calcium