The zinc finger of NEMO is a functional ubiquitin-binding domain.
NEMO (NF-kappaB essential modulator) is a regulatory protein essential to the canonical NF-kappaB signaling pathway, notably involved in immune and inflammatory responses, apoptosis, and oncogenesis. Here, we report that the zinc finger (ZF) motif, located in the regulatory C-terminal half of NEMO, forms a specific complex with ubiquitin. We have investigated the NEMO ZF-ubiquitin interaction and proposed a structural model of the complex based on NMR, fluorescence, and mutagenesis data and on the sequence homology with the polymerase eta ubiquitin-binding zinc finger involved in DNA repair. Functional complementation assays and in vivo pull-down experiments further show that ZF residues involved in ubiquitin binding are functionally important and required for NF-kappaB signaling in response to tumor necrosis factor-alpha. Thus, our findings indicate that NEMOZFisa bona fide ubiquitin-binding domain of the ubiquitin-binding zinc finger type.
Cordier
Florence
F
Institut Pasteur, UnitédeRésonance Magnétique Nucleaire des Biomolécules, 25/28 rue du Dr. Roux, F-75015 Paris, France. Electronic address: fcordier@pasteur.fr.
Grubisha
Olivera
O
Institut Pasteur, Unité de Biochimie Structurale et Cellulaire, CNRS, URA 2185, 25/28 rue du Dr. Roux, F-75015 Paris, France.
Traincard
François
F
Institut Pasteur, Unité de Biochimie Structurale et Cellulaire, CNRS, URA 2185, 25/28 rue du Dr. Roux, F-75015 Paris, France.
Véron
Michel
M
Institut Pasteur, Unité de Biochimie Structurale et Cellulaire, CNRS, URA 2185, 25/28 rue du Dr. Roux, F-75015 Paris, France.
Delepierre
Muriel
M
Institut Pasteur, UnitédeRésonance Magnétique Nucleaire des Biomolécules, 25/28 rue du Dr. Roux, F-75015 Paris, France.
Agou
Fabrice
F
Institut Pasteur, Unité de Biochimie Structurale et Cellulaire, CNRS, URA 2185, 25/28 rue du Dr. Roux, F-75015 Paris, France. Electronic address: fagou@pasteur.fr.
D000595:Amino Acid Sequence; D001665:Binding Sites; D015153:Blotting, Western; D002460:Cell Line; D005816:Genetic Complementation Test; D006801:Humans; D047468:Immunoprecipitation; D019169:Jurkat Cells; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D017386:Sequence Homology, Amino Acid; D025801:Ubiquitin / Q000737:chemistry / Q000378:metabolism*; D016335:Zinc Fingers
D025801:Ubiquitin