Similar effects of electroporational stress and treatment with the phorbolester 12-O-tetradecanoylphorbol-13-acetate on vimentin expression in mouseplasmacytoma cells

In mouse plasmacytoma cells (MPC-11), an activation of the normally repress ed vimentin gene was observed as a response to transfectional stress. Effec ts of electroporation on vimentin gene expression were compared at the cell ular and chromatin level to those caused by treatment with 12-O-tetradecano ylphorbol-13-acetate (TPA). At the cellular level, similar changes in vimen tin gene activity and cell-cycle distribution were observed by flow cytomet ry, whereas at the chromatin level similar changes in patterns of hypersens itive regions were detected by DNase I mapping. Additionally, a region loca ted 700 bp upstream of the transcriptional start became hypersensitive to D Nase I digestion upon electroporation and TPA treatment. This region overla ps two adjacent AP-1-like binding elements and generates specific DNA/AP-1 complexes in bandshift experiments. Therefore, the transcription factor AP- 1 seems to play a central role in the activation of vimentin gene expressio n induced by these 2 different forms of stress. (C) 2000 Elsevier Science B .V. All rights reserved.