RCSB PDB - 3VUW: Crystal structure of A20 ZF7 in complex with linear ubiquitin, form I (original) (raw)
Specific recognition of linear polyubiquitin by A20 zinc finger 7 is involved in NF-kappaB regulation
[Tokunaga, F.](/search?q=citation.rcsb%5Fauthors:Tokunaga, F.), [Nishimasu, H.](/search?q=citation.rcsb%5Fauthors:Nishimasu, H.), [Ishitani, R.](/search?q=citation.rcsb%5Fauthors:Ishitani, R.), [Goto, E.](/search?q=citation.rcsb%5Fauthors:Goto, E.), [Noguchi, T.](/search?q=citation.rcsb%5Fauthors:Noguchi, T.), [Mio, K.](/search?q=citation.rcsb%5Fauthors:Mio, K.), [Kamei, K.](/search?q=citation.rcsb%5Fauthors:Kamei, K.), [Ma, A.](/search?q=citation.rcsb%5Fauthors:Ma, A.), [Iwai, K.](/search?q=citation.rcsb%5Fauthors:Iwai, K.), [Nureki, O.](/search?q=citation.rcsb%5Fauthors:Nureki, O.)
(2012) EMBO J 31: 3856-3870
PubMed Abstract:
LUBAC (linear ubiquitin chain assembly complex) activates the canonical NF-κB pathway through linear polyubiquitination of NEMO (NF-κB essential modulator, also known as IKKγ) and RIP1. However, the regulatory mechanism of LUBAC-mediated NF-κB activation remains elusive. Here, we show that A20 suppresses LUBAC-mediated NF-κB activation by binding linear polyubiquitin via the C-terminal seventh zinc finger (ZF7), whereas CYLD suppresses it through deubiquitinase (DUB) activity. We determined the crystal structures of A20 ZF7 in complex with linear diubiquitin at 1.70-1.98 Å resolutions. The crystal structures revealed that A20 ZF7 simultaneously recognizes the Met1-linked proximal and distal ubiquitins, and that genetic mutations associated with B cell lymphomas map to the ubiquitin-binding sites. Our functional analysis indicated that the binding of A20 ZF7 to linear polyubiquitin contributes to the recruitment of A20 into a TNF receptor (TNFR) signalling complex containing LUBAC and IκB kinase (IKK), which results in NF-κB suppression. These findings provide new insight into the regulation of immune and inflammatory responses.
Organizational Affiliation:
Laboratory of Molecular Cell Biology, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma, Japan. ftokunaga@gunma-u.ac.jp