The NF-kappa B p50 precursor, p105, contains an internal I kappa B-like inhibitor that preferentially inhibits p50.

摘要: Abstract The p50 subunit of NF-kappa B is apparently synthesized as a precursor molecule 105 kDa (p105); subsequent processing releases the amino-terminal polypeptide with rel homology, DNA binding activity and transcriptional activation potential. The carboxy-terminal region p105 contains seven copies an ankyrin-related sequence previously found in several genes involved differentiation cell cycle control. Two proteins I kappa activity, MAD-3 pp40, have been cloned to contain five obvious ankyrin repeats that align those carboxy-terminus p105. Both target their inhibitory p65 c-rel. Here we show bacterially expressed purified (CTR) abolishes homodimers motif but minimally affects B. By contrast, inhibits not p50. CTR interact respective targets through physical association both vitro vivo. can be independent entity thus may play two roles, cis inhibitor built into trans regulator