IkappaB kinase beta promotes cell survival by antagonizing p53 functions through DeltaNp73alpha phosphorylation and stabilization.

ABSTRACT: ΔNp73α, a dominant-negative inhibitor of p53 and p73, exhibits antiapoptotic and transforming activity in in vitro models and is often found to be upregulated in human cancers. The mechanisms involved in the regulation of ΔNp73α protein levels in normal and cancer cells are poorly characterized. Here, we show that that IκB kinase beta (IKKβ) increases ΔNp73α protein stability independently of its ability to activate NF-κB. IKKβ associates with and phosphorylates ΔNp73α at serine 422 (S422), leading to its accumulation in the nucleus, where it binds and represses several p53-regulated genes. S422A mutation in ΔNp73α abolished IKKβ-mediated stabilization and inhibition of p53-regulated gene expression. Inhibition of IKKβ activity by chemical inhibitors, overexpression of dominant-negative mu

SUBMITTER: Accardi R 

PROVIDER: S-EPMC3133237 | biostudies-literature | 2011 Jun

REPOSITORIES: biostudies-literature