As a latent transcription factor,NF-κB translocates from cytoplasm into nucleus upon stimulations and mediates expression of genes important in immunity,inflammation and development.However,little is known about how it is regulated inside nucleus.By two-hybrid approach,we identify a prefoldin-like protein UXT that is expressed predominantly and interacts specifically with NF-κB inside nucleus.RNAi knockdown of UXT leads to impaired NF-κB activity and dramatically attenuates expression of NF-κB dependent genes.This interference also sensitizes cells to apoptosis by TNF-α.Furthermore,UXT forms a dynamic complex with NF-κB and is recruited to the NF-κB enhanceosome upon stimulation.