Mapping DNA-protein interactions in cells and nuclei: genomic sequencing by template purification

Tissue-specific chromatin structure at the hepatocyte growth factor/scatter factor gene promoter

Hepatocyte growth factor/scatter factor (HGF/SF) is a recently characterised molecule with many remarkable functions. Its involvement in important processes such as cell proliferation, cell migration, morphogenesis and organ development implies that its activity should be tightly regulated. To understand the molecular mechanisms controlling HGF/SF transcription, we have analysed DNaseI hypersensitive sites (DHS) along rat and human HGF/SF genes in various tissues and cell types. We identified five DHS along the rat gene, two in the 5'-flanking region and three in the first intron. These sites are only found in rat tissues and rat cell lines, which express HGF/SF. The strongest hypersensitive site map to a region that corresponds to the promoter by start site analysis. A single tissue-specific DHS is present in human cell lines that express HGF/SF and corresponds to the promoter region. Our results suggest that chromatin accessibility plays a major role in the regulation of HGF/SF transcription regulation.

The role of chromatin in HIV-1 transcriptional regulation

Regulation of transcription is a key feature of the HIV-1 life cycle. In recent years, various sequence elements and transcription factors have been shown to participate in HIV-1 transcription control. New evidence, however, has shown that chromatin organization plays a key role in the establishment of a transcriptionally regulated HIV-1 LTR. The present review discusses recent data obtained on reconstituted and genomic HIV-1 chromatin templates.