Targeted disruption of the ζPKC gene results in the impairment of the NF-κB pathway

Here we have addressed the role that PKC plays in NF-kappaB activation using mice in which this kinase was inactivated by homologous recombination. These mice, although grossly normal, showed phenotypic alterations in secondary lymphoid organs reminiscent of those of the TNF receptor-1 and of the lymphotoxin-beta receptor gene-deficient mice. The lack of xi PKC in embryonic fibroblasts (EFs) severely impairs kappaB-dependent transcriptional activity as well as cytokine-induced phosphorylation of p65. Also, a cytokine-inducible interaction of xi PKC with p65 was detected which requires the previous degradation Of I kappaB. Although in xi PKC-/- EFs this kinase is not necessary for IKK activation, in lung, which abundantly expresses xi PKC, IKK activation is inhibited.