Functional analysis and growth factor regulation of the human vimentin promoter

Vimentin is a growth-regulated gene whose mRNA levels increase severalfold after stimulation of quiescent cells. We have isolated and sequenced a genomic fragment of human DNA containing the vimentin 5'-flanking sequence and untranslated region. S1 nuclease analysis was used to determine the transcription initiation site. Deletion mutants of the promoter region were constructed, linked to a chloramphenicol acetyltransferase gene, and analyzed for transient expression by transfection into BALB/c 3T3 cells. These experiments revealed the presence in the human vimentin promoter region of a negative-regulatory element, flanked by positive elements. The most 5' of the positive elements is able to overcome the effects of the negative element. Analysis of these deletion constructs in stable cell lines confirmed the results of the transient assays. Using these stable cell lines, we can also demonstrate that the vimentin promoter region can confer platelet-derived growth factor inducibility to a linked chloramphenicol acetyltransferase gene and that the sequences required for this inducibility reside between positions -241 and +73.