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-κB Activation
The NEMO ( N F-κB e ssential mo dulator) protein plays a crucial role in the canonical NF-κB pathway as the regulatory component of the IKK ( Iκ B k inase) complex. The human disease anhidrotic ectodermal dysplasia with immunodeficiency (EDA-ID) has been recently linked to mutations in NEMO. We i...
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| Published in: | The Journal of biological chemistry Vol. 281; no. 10; p. 6334 |
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| Main Authors: | , , , , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
American Society for Biochemistry and Molecular Biology
10-03-2006
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| Online Access: | Get full text |
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| Summary: | The NEMO ( N F-κB e ssential mo dulator) protein plays a crucial role in the canonical NF-κB pathway as the regulatory component of the IKK ( Iκ B k inase) 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-α and LPS-induced NF-κB 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. |
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| ISSN: | 0021-9258 1083-351X |
| DOI: | 10.1074/jbc.M510118200 |