A20 inhibits NF-kappaB activation independently of binding to 14-3-3 proteins.
The A20 protein, which belongs to a class of Cys2/Cys2 zinc finger proteins, has been characterized as an inhibitor of NF-kappaB activation. In order to clarify its molecular mechanism of action, the yeast two-hybrid system was used to screen for interacting proteins. We report that different isoforms of 14-3-3 proteins, viz. eta and zeta, are able to bind A20, involving the 14-3-3-binding motif RSKSDP located between zinc fingers 3 and 4. However, A20 mutants that no longer associated with 14-3-3 proteins could still fully inhibit NF-kappaB activation induced by tumor necrosis factor, interleukin-1beta or phorbol 12-myristate 13-acetate, thus excluding a crucial role for 14-3-3 interaction in this A20 function.
De Valck
D
D
Laboratory of Molecular Biology, Flanders Interuniversity Institute for Biotechnology, University of Ghent, K. L. Ledeganckstraat 35, Ghent, B-9000, Belgium.
Heyninck
K
K
Van Criekinge
W
W
Vandenabeele
P
P
Fiers
W
W
Beyaert
R
R
D048948:14-3-3 Proteins; D001665:Binding Sites; D002460:Cell Line; D004268:DNA-Binding Proteins; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins; D011485:Protein Binding; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D000072598:Tumor Necrosis Factor alpha-Induced Protein 3; D014446:Tyrosine 3-Monooxygenase; D016335:Zinc Fingers
D048948:14-3-3 Proteins; D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D016328:NF-kappa B; D009687:Nuclear Proteins; D011506:Proteins; D014446:Tyrosine 3-Monooxygenase; C076529:TNFAIP3 protein, human; D000072598:Tumor Necrosis Factor alpha-Induced Protein 3