Insulators are a new class of genetic elements that attenuate enhancer function directionally. Previously, we characterized in sea urchin a 265-bp-long insulator, termed sns. To test insulator activity following stable integration in human cells, we placed sns between the CMV enhancer and a tk promoter up-stream of a GFP transgene of plasmid or retroviral vectors. In contrast to controls, cells transfected or transduced with insulated constructs displayed a barely detectable fluorescence. Southern blot and PCR ruled out vector rearrangement following integration into host DNA; RNase protection confirmed the enhancer blocking activity. Finally, we demonstrate that two cis-acting sequences, previously characterized in sea urchin, are also specific binding sites for human proteins. We conclude that sns interferes with enhancer promoter interaction also in a human chromatin context. The relatively small size, evolutionary conservation and apparent lack of enhancer specificity might result useful in gene transfer experiments in human cells. © 2001 Academic Press.
|Number of pages||6|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - 2001|
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology