MEMBERS OF THE REL/NF-KAPPA-B-FAMILY OF TRANSCRIPTIONAL REGULATORY PROTEINS BIND THE HRAS1 MINISATELLITE DNA-SEQUENCE

The 28 base pair repeat unit of a minisatellite 1000 bp downstream from the human HRAS1 gene (VTR(HRAS1)) bound four proteins (p45, p50, p72 and p85) in nuclear extracts from a variety of human cell lines which were indistinguishable from several members of the rel/NF-chi-B family of transcriptional regulatory factors. VTR(HRAS1) bound the constitutively expressed, but not the inducible, forms of these proteins. Analysis of partially purified binding factors from different cell lines demonstrated qualitative differences in the p50 subunit; phosphocellulose fractionation also revealed considerable heterogeneity in the p72 and p85 subunits. These results suggest the possibility that the HRAS1 minisatellite, in serving as a tandem array of rel/NF-chi-B binding sites, may function in the transcriptional regulation of HRAS1 and nearby genes.