A novel complex between the p65 subunit of NF-kappa B and c-Rel binds to a DNA element involved in the phorbol ester induction of the human urokinase gene.

摘要: The NF-kappa B subunits, p50 and p65, have extensive sequence homology with the c-rel proto-oncogene Drosophila morphogen dorsal. It has recently been shown that in vitro translated c-Rel can bind to DNA form a complex p50. However, conditions for binding of vivo its specificity not established. Here we report identification novel heterodimeric binds kappa B-like, phorbol ester (TPA) responsive sequence, 5'-GGGAAAGTAC-3', 5' flanking region human urokinase (uPA) gene. This was two protein complexes, LC UC. indistinguishable from as it reacted antibodies recognizing subunit B, by UV crosslinking contain p65 subunits B. UC, on other hand, strongly anti-v-Rel, but anti-p50 antibodies, 75 kDa 85 protein-DNA adducts. adducts could be immunoprecipitated only anti-p65 anti-c-Rel respectively, showing formed heterodimer p65. Both complexes were present inactive forms HeLa cell cytosol, their nuclear translocation induced TPA. UC could, furthermore, inhibited I B-alpha.(ABSTRACT TRUNCATED AT 250 WORDS)