Casein kinase II-mediated phosphorylation of NF-kappaB p65 subunit enhances inducible nitric-oxide synthase gene transcription in vivo.

Nitric oxide (NO) produced by inducible nitric-oxide synthase (NOSII) is mainly regulated at the transcriptional level by the nuclear factor-kappaB (NF-kappaB). In the present study, we further analyzed the role of NF-kappaB in the in vivo transcriptional regulation of NOSII gene by comparing two clones isolated from the EMT-6 mouse mammary cancer cell line. In response to interleukin (IL)-1beta or lipopolysaccharide (LPS), EMT-6 clone J (EMT-6J) cells produce 3-fold more NO than EMT-6 clone H (EMT-6H) cells, an effect correlated with enhanced activation of NF-kappaB in EMT-6J cells.