Identification of a new NEMO/TRAF6 interface affected in incontinentia pigmenti pathology

• Published in: Human molecular genetics 2010-08, Vol.19 (16), p.3138-3149
• Main Authors: Gautheron, Jérémie, Pescatore, Alessandra, Fusco, Francesca, Esposito, Elio, Yamaoka, Shoji, Agou, Fabrice, Ursini, Matilde Valeria, Courtois, Gilles
• Format: Article
• Language: English
• Subjects: Amino Acid Substitution; Animals; Binding Sites; Binding Sites - genetics; Biological and medical sciences; Blotting, Western; Cell Line; Cells, Cultured; Dermatology; Embryo, Mammalian; Embryo, Mammalian - cytology; Fibroblasts; Fibroblasts - cytology; Fibroblasts - drug effects; Fibroblasts - metabolism; Fundamental and applied biological sciences. Psychology; Genetics of eukaryotes. Biological and molecular evolution; Humans; I-kappa B Kinase; I-kappa B Kinase - chemistry; I-kappa B Kinase - genetics; I-kappa B Kinase - metabolism; Immunoprecipitation; Incontinentia Pigmenti; Incontinentia Pigmenti - genetics; Incontinentia Pigmenti - metabolism; Incontinentia Pigmenti - pathology; Interleukin-1beta; Interleukin-1beta - pharmacology; Intracellular Signaling Peptides and Proteins; Intracellular Signaling Peptides and Proteins - chemistry; Intracellular Signaling Peptides and Proteins - genetics; Intracellular Signaling Peptides and Proteins - metabolism; Life Sciences; Medical sciences; Mice; Mice, Knockout; Models, Molecular; Molecular and cellular biology; Mutation; Pigmentary diseases of the skin; Protein Binding; Protein Binding - drug effects; Protein Structure, Tertiary; TNF Receptor-Associated Factor 6; TNF Receptor-Associated Factor 6 - genetics; TNF Receptor-Associated Factor 6 - metabolism
• ISSN: 0964-6906; 1460-2083
• DOI: 10.1093/hmg/ddq222

NF-κB Essential MOdulator (NEMO) has been shown to play a critical role in NF-κB activation, as the regulatory subunit of IκB kinase. Upon cell stimulation, NEMO can be modified through phosphorylation, sumoylation or ubiquitination. In the latter case, not much is known regarding the exact function of this posttranslational modification. One of the E3 ligase responsible for K63-linked NEMO polyubiquitination is TRAF6, which participates in several signaling pathways controlling immunity, osteoclastogenesis, skin development and brain functions. We previously observed a potentially important interaction between NEMO and TRAF6. In this study, we defined in more detail the domains required for this interaction, uncovering a new binding site for TRAF6 located at the amino-terminus of NEMO and recognized by the coiled-coil domain of TRAF6. This site appears to work in concert with the previously identified NEMO ubiquitin-binding domain which binds polyubiquitinated chains, suggesting a dual mode of TRAF6 recognition. We also showed that E57K mutation of NEMO found in a mild form of the genetic disease incontinentia pigmenti, resulted in impaired TRAF6 binding and IL-1β signaling. In contrast, activation of NF-κB by TNF-α was not affected. These data demonstrate that NEMO/TRAF6 interaction has physiological relevance and might represent a new target for therapeutic purposes.