An antisilencer element is involved in the transcriptional regulation of the human vimentin gene.

Vimentin is an intermediate filament protein normally expressed in cells of mesenchymal origin. The promoter of the human vimentin gene was previously reported to contain two positive-acting regions, separated by a negative region (Rittling, S.R., Baserga, R., 1987. Functional analysis and growth factor regulation of the human vimentin promoter. Mol. Cell. Biol. 7, 3908-3915). Here, detailed studies reveal two additional regulatory elements, a new positive transcriptional element located between -717 and -757, and a new repressor element at -780 to -821. In transient transfections, the positive-acting element is able to completely override the effect of different silencer elements when fused to a heterologous promoter. However, this element does not enhance gene activity when the silencer element is absent and thus cannot be viewed as a true enhancer. Since it appears to overcome the effect of a silencer element, we refer to it as an antisilencer element. Gel mobility shift assays, UV-cross-linking experiments, and Southwestern blots reveal that a 105-kDa protein specifically binds to this region.