A point mutation in NEMO associated with anhidrotic ectodermal dysplasia with immunodeficiency pathology results in destabilization of the oligomer and reduces lipopolysaccharide- and tumor necrosis factor-mediated NF-kappa B activation

J Biol Chem. 2006 Mar 10;281(10):6334-48. doi: 10.1074/jbc.M510118200. Epub 2005 Dec 26.


The NEMO (NF-kappaB essential modulator) protein plays a crucial role in the canonical NF-kappaB pathway as the regulatory component of the IKK (IkappaB kinase) complex. The human disease anhidrotic ectodermal dysplasia with immunodeficiency (EDA-ID) has been recently linked to mutations in NEMO. We investigated the effect of an alanine to glycine substitution found in the NEMO polypeptide of an EDA-ID patient. This pathogenic mutation is located within the minimal oligomerization domain of the protein, which is required for the IKK activation in response to diverse stimuli. The mutation does not dramatically change the native-like state of the trimer, but temperature-induced unfolding studied by circular dichroism showed that it leads to an important loss in the oligomer stability. Furthermore, fluorescence studies showed that the tyrosine located in the adjacent zinc finger domain, which is possibly required for NEMO ubiquitination, exhibits an alteration in its spectral properties. This is probably due to a conformational change of this domain, providing evidence for a close interaction between the oligomerization domain and the zinc finger. In addition, functional complementation assays using NEMO-deficient pre-B and T lymphocytes showed that the pathogenic mutation reduced TNF-alpha and LPS-induced NF-kappaB activation by altering the assembly of the IKK complex. Altogether, our findings provide understanding as to how a single point mutation in NEMO leads to the observed EDA-ID phenotype in relation to the NEMO-dependent mechanism of IKK activation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Line
  • Circular Dichroism
  • Ectodermal Dysplasia / genetics*
  • Ectodermal Dysplasia / pathology
  • Humans
  • I-kappa B Kinase / chemistry
  • I-kappa B Kinase / deficiency
  • I-kappa B Kinase / genetics*
  • I-kappa B Kinase / metabolism
  • Immunologic Deficiency Syndromes / genetics*
  • Immunologic Deficiency Syndromes / pathology
  • Lipopolysaccharides / antagonists & inhibitors*
  • Lipopolysaccharides / pharmacology
  • Mice
  • Molecular Sequence Data
  • NF-kappa B / antagonists & inhibitors*
  • NF-kappa B / metabolism
  • Point Mutation*
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification
  • Temperature
  • Tumor Necrosis Factor-alpha / antagonists & inhibitors*
  • Tumor Necrosis Factor-alpha / physiology*
  • Tyrosine / genetics
  • Zinc Fingers / genetics


  • IKBKG protein, human
  • Lipopolysaccharides
  • NF-kappa B
  • Recombinant Proteins
  • Tumor Necrosis Factor-alpha
  • Tyrosine
  • I-kappa B Kinase