IKK-i, a novel lipopolysaccharide-inducible kinase that is related to IkappaB kinases

Int Immunol. 1999 Aug;11(8):1357-62. doi: 10.1093/intimm/11.8.1357.


Using the suppression subtractive hybridization technique, we isolated a novel kinase, IKK-i, whose message is drastically induced by lipopolysaccharide (LPS) in the mouse macrophage cell line RAW264. 7. The predicted protein contains the kinase domain in its N-terminus, which shares 30% identity to that of IKK-alpha or IKK-beta. The C-terminal portion contains a leucine zipper and a potential helix-loop-helix domain, as in the case of IKK-alpha and IKK-beta. IKK-i is expressed mainly in immune cells, and is induced in response to proinflammatory cytokines such as tumor necrosis factor-alpha, IL-1 and IL-6, in addition to LPS. Overexpression of wild-type IKK-i phosphorylated serine residues Ser32 and Ser36 of IkappaB-alpha (preferentially Ser36), and significantly stimulated NF-kappaB activation. These results suggest that IKK-i is an inducible IkappaB kinase which may play a special role in the immune response.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cytokines / immunology
  • DNA-Binding Proteins / metabolism
  • Enzyme Induction
  • Humans
  • I-kappa B Kinase
  • I-kappa B Proteins*
  • Inflammation / immunology
  • Lipopolysaccharides / pharmacology*
  • Macrophage Activation
  • Macrophages / enzymology*
  • Macrophages / immunology*
  • Mice
  • Molecular Sequence Data
  • NF-KappaB Inhibitor alpha
  • NF-kappa B / metabolism
  • Phosphorylation
  • Protein Serine-Threonine Kinases / chemistry
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism*
  • Sequence Analysis, DNA
  • Transcriptional Activation


  • Cytokines
  • DNA-Binding Proteins
  • I-kappa B Proteins
  • Lipopolysaccharides
  • NF-kappa B
  • NFKBIA protein, human
  • Nfkbia protein, mouse
  • NF-KappaB Inhibitor alpha
  • Protein Serine-Threonine Kinases
  • CHUK protein, human
  • Chuk protein, mouse
  • I-kappa B Kinase
  • IKBKB protein, human
  • IKBKE protein, human
  • Ikbkb protein, mouse
  • Ikbke protein, mouse

Associated data

  • GENBANK/AB016589
  • GENBANK/AB016590